root/sys/arch/shark/ofw/ofw.c
/*      $NetBSD: ofw.c,v 1.69 2023/12/10 23:19:12 andvar Exp $  */

/*
 * Copyright 1997
 * Digital Equipment Corporation. All rights reserved.
 *
 * This software is furnished under license and may be used and
 * copied only in accordance with the following terms and conditions.
 * Subject to these conditions, you may download, copy, install,
 * use, modify and distribute this software in source and/or binary
 * form. No title or ownership is transferred hereby.
 *
 * 1) Any source code used, modified or distributed must reproduce
 *    and retain this copyright notice and list of conditions as
 *    they appear in the source file.
 *
 * 2) No right is granted to use any trade name, trademark, or logo of
 *    Digital Equipment Corporation. Neither the "Digital Equipment
 *    Corporation" name nor any trademark or logo of Digital Equipment
 *    Corporation may be used to endorse or promote products derived
 *    from this software without the prior written permission of
 *    Digital Equipment Corporation.
 *
 * 3) This software is provided "AS-IS" and any express or implied
 *    warranties, including but not limited to, any implied warranties
 *    of merchantability, fitness for a particular purpose, or
 *    non-infringement are disclaimed. In no event shall DIGITAL be
 *    liable for any damages whatsoever, and in particular, DIGITAL
 *    shall not be liable for special, indirect, consequential, or
 *    incidental damages or damages for lost profits, loss of
 *    revenue or loss of use, whether such damages arise in contract,
 *    negligence, tort, under statute, in equity, at law or otherwise,
 *    even if advised of the possibility of such damage.
 */

/*
 *  Routines for interfacing between NetBSD and OFW.
 * 
 *  Parts of this could be moved to an MI file in time. -JJK
 *
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ofw.c,v 1.69 2023/12/10 23:19:12 andvar Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/reboot.h>
#include <sys/mbuf.h>
#include <sys/cpu.h>
#include <sys/intr.h>

#include <uvm/uvm.h>

#include <dev/cons.h>

#define _ARM32_BUS_DMA_PRIVATE
#include <sys/bus.h>

#include <arm/locore.h>

#include <machine/bootconfig.h>
#include <machine/irqhandler.h>

#include <dev/ofw/openfirm.h>
#include <machine/ofw.h>

#include <netinet/in.h>

#if     BOOT_FW_DHCP
#include <nfs/bootdata.h>
#endif

#ifdef SHARK
#include "machine/pio.h"
#include "machine/isa_machdep.h"
#endif

#include "isadma.h"
#include "igsfb_ofbus.h"
#include "chipsfb_ofbus.h"
#include "vga_ofbus.h"

#define IO_VIRT_BASE (OFW_VIRT_BASE + OFW_VIRT_SIZE)
#define IO_VIRT_SIZE 0x01000000

#define KERNEL_IMG_PTS          2
#define KERNEL_VMDATA_PTS       (KERNEL_VM_SIZE >> (L1_S_SHIFT + 2))
#define KERNEL_OFW_PTS          4
#define KERNEL_IO_PTS           4

#define KERNEL_VM_BASE          (KERNEL_BASE + 0x01000000)
/*
 * The range 0xf1000000 - 0xf6ffffff is available for kernel VM space
 * OFW sits at 0xf7000000
 */
#define KERNEL_VM_SIZE          0x06000000

/*
 *  Imported variables
 */
extern BootConfig bootconfig;   /* temporary, I hope */

#ifdef  DIAGNOSTIC
/* NOTE: These variables will be removed, well some of them */
extern u_int current_mask;
#endif

extern int ofw_handleticks;


/*
 *  Imported routines
 */
extern void dump_spl_masks(void);
extern void dumpsys(void);
extern void dotickgrovelling(vaddr_t);

#define WriteWord(a, b) \
*((volatile unsigned int *)(a)) = (b)

#define ReadWord(a) \
(*((volatile unsigned int *)(a)))


/*
 *  Exported variables
 */
/* These should all be in a meminfo structure. */
paddr_t physical_start;
paddr_t physical_freestart;
paddr_t physical_freeend;
paddr_t physical_end;
u_int free_pages;

paddr_t msgbufphys;

/* for storage allocation, used to be local to ofw_construct_proc0_addrspace */
static vaddr_t  virt_freeptr;

int ofw_callbacks = 0;          /* debugging counter */

#if (NIGSFB_OFBUS > 0) || (NCHIPSFB_OFBUS > 0) || (NVGA_OFBUS > 0)
int console_ihandle = 0;
static void reset_screen(void);
#endif

/**************************************************************/


/*
 *  Declarations and definitions private to this module
 *
 */

struct mem_region {
        paddr_t start;
        psize_t size;
};

struct mem_translation {
        vaddr_t virt;
        vsize_t size;
        paddr_t phys;
        unsigned int mode;
};

struct isa_range {
        paddr_t isa_phys_hi;
        paddr_t isa_phys_lo;
        paddr_t parent_phys_start;
        psize_t isa_size;
};

struct vl_range {
        paddr_t vl_phys_hi;
        paddr_t vl_phys_lo;
        paddr_t parent_phys_start;
        psize_t vl_size;
};

struct vl_isa_range {
        paddr_t isa_phys_hi;
        paddr_t isa_phys_lo;
        paddr_t parent_phys_hi;
        paddr_t parent_phys_lo;
        psize_t isa_size;
};

struct dma_range {
        paddr_t start;
        psize_t   size;
};

struct ofw_cbargs {
        char *name;
        int nargs;
        int nreturns;
        int args_n_results[12];
};


/* Memory info */
static int nOFphysmem;
static struct mem_region *OFphysmem;
static int nOFphysavail;
static struct mem_region *OFphysavail;
static int nOFtranslations;
static struct mem_translation *OFtranslations;
static int nOFdmaranges;
static struct dma_range *OFdmaranges;

/* The OFW client services handle. */
/* Initialized by ofw_init(). */
static ofw_handle_t ofw_client_services_handle;


static void ofw_callbackhandler(void *);
static void ofw_construct_proc0_addrspace(void);
static void ofw_getphysmeminfo(void);
static void ofw_getvirttranslations(void);
static void *ofw_malloc(vsize_t size);
static void ofw_claimpages(vaddr_t *, pv_addr_t *, vsize_t);
static void ofw_discardmappings(vaddr_t, vaddr_t, vsize_t);
static int ofw_mem_ihandle(void);
static int ofw_mmu_ihandle(void);
static paddr_t ofw_claimphys(paddr_t, psize_t, paddr_t);
#if 0
static paddr_t ofw_releasephys(paddr_t, psize_t);
#endif
static vaddr_t ofw_claimvirt(vaddr_t, vsize_t, vaddr_t);
static void ofw_settranslation(vaddr_t, paddr_t, vsize_t, int);
static void ofw_initallocator(void);
static void ofw_configisaonly(paddr_t *, paddr_t *);
static void ofw_configvl(int, paddr_t *, paddr_t *);
static vaddr_t ofw_valloc(vsize_t, vaddr_t);


/*
 * DHCP hooks.  For a first cut, we look to see if there is a DHCP
 * packet that was saved by the firmware.  If not, we proceed as before,
 * getting hand-configured data from NVRAM.  If there is one, we get the
 * packet, and extract the data from it.  For now, we hand that data up
 * in the boot_args string as before.
 */


/**************************************************************/


/*
 *
 *  Support routines for xxx_machdep.c
 *
 *  The intent is that all OFW-based configurations use the
 *  exported routines in this file to do their business.  If
 *  they need to override some function they are free to do so.
 *
 *  The exported routines are:
 *
 *    openfirmware
 *    ofw_init
 *    ofw_boot
 *    ofw_getbootinfo
 *    ofw_configmem
 *    ofw_configisa
 *    ofw_configisadma
 *    ofw_gettranslation
 *    ofw_map
 *    ofw_getcleaninfo
 */


int
openfirmware(void *args)
{
        int ofw_result;
        u_int saved_irq_state;

        /* OFW is not re-entrant, so we wrap a mutex around the call. */
        saved_irq_state = disable_interrupts(I32_bit);
        ofw_result = ofw_client_services_handle(args);
        (void)restore_interrupts(saved_irq_state);

        return(ofw_result);
}


void
ofw_init(ofw_handle_t ofw_handle)
{
        ofw_client_services_handle = ofw_handle;

        /*  Everything we allocate in the remainder of this block is
         *  constrained to be in the "kernel-static" portion of the
         *  virtual address space (i.e., 0xF0000000 - 0xF1000000).
         *  This is because all such objects are expected to be in
         *  that range by NetBSD, or the objects will be re-mapped
         *  after the page-table-switch to other specific locations.
         *  In the latter case, it's simplest if our pre-switch handles
         *  on those objects are in regions that are already "well-
         *  known."  (Otherwise, the cloning of the OFW-managed address-
         *  space becomes more awkward.)  To minimize the number of L2
         *  page tables that we use, we are further restricting the
         *  remaining allocations in this block to the bottom quarter of
         *  the legal range.  OFW will have loaded the kernel text+data+bss
         *  starting at the bottom of the range, and we will allocate
         *  objects from the top, moving downwards.  The two sub-regions
         *  will collide if their total sizes hit 8MB.  The current total
         *  is <1.5MB, but INSTALL kernels are > 4MB, so hence the 8MB
         *  limit.  The variable virt-freeptr represents the next free va
         *  (moving downwards).
         */
        virt_freeptr = KERNEL_BASE + (0x00400000 * KERNEL_IMG_PTS);
}


void
ofw_boot(int howto, char *bootstr)
{

#ifdef DIAGNOSTIC
        printf("boot: howto=%08x curlwp=%p\n", howto, curlwp);
        printf("current_mask=%08x\n", current_mask);

        printf("ipl_bio=%08x ipl_net=%08x ipl_tty=%08x ipl_vm=%08x\n",
            irqmasks[IPL_BIO], irqmasks[IPL_NET], irqmasks[IPL_TTY],
            irqmasks[IPL_VM]);
        printf("ipl_clock=%08x ipl_none=%08x\n",
            irqmasks[IPL_CLOCK], irqmasks[IPL_NONE]);

        dump_spl_masks();
#endif

        /*
         * If we are still cold then hit the air brakes
         * and crash to earth fast
         */
        if (cold) {
                doshutdownhooks();
                pmf_system_shutdown(boothowto);
                printf("Halted while still in the ICE age.\n");
                printf("The operating system has halted.\n");
                goto ofw_exit;
                /*NOTREACHED*/
        }

        /*
         * If RB_NOSYNC was not specified sync the discs.
         * Note: Unless cold is set to 1 here, syslogd will die during the unmount.
         * It looks like syslogd is getting woken up only to find that it cannot
         * page part of the binary in as the filesystem has been unmounted.
         */
        if (!(howto & RB_NOSYNC))
                bootsync();

        /* Say NO to interrupts */
        splhigh();

        /* Do a dump if requested. */
        if ((howto & (RB_DUMP | RB_HALT)) == RB_DUMP)
                dumpsys();
        
        /* Run any shutdown hooks */
        doshutdownhooks();

        pmf_system_shutdown(boothowto);

        /* Make sure IRQ's are disabled */
        IRQdisable;

        if (howto & RB_HALT) {
                printf("The operating system has halted.\n");
                goto ofw_exit;
        }

        /* Tell the user we are booting */
        printf("rebooting...\n");

        /* Jump into the OFW boot routine. */
        {
                static char str[256];
                char *ap = str, *ap1 = ap;

                if (bootstr && *bootstr) {
                        if (strlen(bootstr) > sizeof str - 5)
                                printf("boot string too large, ignored\n");
                        else {
                                strcpy(str, bootstr);
                                ap1 = ap = str + strlen(str);
                                *ap++ = ' ';
                        }
                }
                *ap++ = '-';
                if (howto & RB_SINGLE)
                        *ap++ = 's';
                if (howto & RB_KDB)
                        *ap++ = 'd';
                *ap++ = 0;
                if (ap[-2] == '-')
                        *ap1 = 0;
#if (NIGSFB_OFBUS > 0) || (NCHIPSFB_OFBUS > 0) || (NVGA_OFBUS > 0)
                reset_screen();
#endif
                OF_boot(str);
                /*NOTREACHED*/
        }

ofw_exit:
        printf("Calling OF_exit...\n");
#if (NIGSFB_OFBUS > 0) || (NCHIPSFB_OFBUS > 0) || (NVGA_OFBUS > 0)
        reset_screen();
#endif
        OF_exit();
        /*NOTREACHED*/
}


#if     BOOT_FW_DHCP

extern  char    *ip2dotted(struct in_addr);

/*
 * Get DHCP data from OFW
 */

void
get_fw_dhcp_data(struct bootdata *bdp)
{
        int chosen;
        int dhcplen;

        memset((char *)bdp, 0, sizeof(*bdp));
        if ((chosen = OF_finddevice("/chosen")) == -1)
                panic("no /chosen from OFW");
        if ((dhcplen = OF_getproplen(chosen, "bootp-response")) > 0) {
                u_char *cp;
                int dhcp_type = 0;
                char *ip;

                /*
                 * OFW saved a DHCP (or BOOTP) packet for us.
                 */
                if (dhcplen > sizeof(bdp->dhcp_packet))
                        panic("DHCP packet too large");
                OF_getprop(chosen, "bootp-response", &bdp->dhcp_packet,
                    sizeof(bdp->dhcp_packet));
                SANITY(bdp->dhcp_packet.op == BOOTREPLY, "bogus DHCP packet");
                /*
                 * Collect the interesting data from DHCP into
                 * the bootdata structure.
                 */
                bdp->ip_address = bdp->dhcp_packet.yiaddr;
                ip = ip2dotted(bdp->ip_address);
                if (memcmp(bdp->dhcp_packet.options, DHCP_OPTIONS_COOKIE, 4) == 0)
                        parse_dhcp_options(&bdp->dhcp_packet,
                            bdp->dhcp_packet.options + 4,
                            &bdp->dhcp_packet.options[dhcplen
                            - DHCP_FIXED_NON_UDP], bdp, ip);
                if (bdp->root_ip.s_addr == 0)
                        bdp->root_ip = bdp->dhcp_packet.siaddr;
                if (bdp->swap_ip.s_addr == 0)
                        bdp->swap_ip = bdp->dhcp_packet.siaddr;
        }
        /*
         * If the DHCP packet did not contain all the necessary data,
         * look in NVRAM for the missing parts.
         */
        {
                int options;
                int proplen;
#define BOOTJUNKV_SIZE  256
                char bootjunkv[BOOTJUNKV_SIZE]; /* minimize stack usage */


                if ((options = OF_finddevice("/options")) == -1)
                        panic("can't find /options");
                if (bdp->ip_address.s_addr == 0 &&
                    (proplen = OF_getprop(options, "ipaddr",
                    bootjunkv, BOOTJUNKV_SIZE - 1)) > 0) {
                        bootjunkv[proplen] = '\0';
                        if (dotted2ip(bootjunkv, &bdp->ip_address.s_addr) == 0)
                                bdp->ip_address.s_addr = 0;
                }
                if (bdp->ip_mask.s_addr == 0 &&
                    (proplen = OF_getprop(options, "netmask",
                    bootjunkv, BOOTJUNKV_SIZE - 1)) > 0) {
                        bootjunkv[proplen] = '\0';
                        if (dotted2ip(bootjunkv, &bdp->ip_mask.s_addr) == 0)
                                bdp->ip_mask.s_addr = 0;
                }
                if (bdp->hostname[0] == '\0' &&
                    (proplen = OF_getprop(options, "hostname",
                    bdp->hostname, sizeof(bdp->hostname) - 1)) > 0) {
                        bdp->hostname[proplen] = '\0';
                }
                if (bdp->root[0] == '\0' &&
                    (proplen = OF_getprop(options, "rootfs",
                    bootjunkv, BOOTJUNKV_SIZE - 1)) > 0) {
                        bootjunkv[proplen] = '\0';
                        parse_server_path(bootjunkv, &bdp->root_ip, bdp->root);
                }
                if (bdp->swap[0] == '\0' &&
                    (proplen = OF_getprop(options, "swapfs",
                    bootjunkv, BOOTJUNKV_SIZE - 1)) > 0) {
                        bootjunkv[proplen] = '\0';
                        parse_server_path(bootjunkv, &bdp->swap_ip, bdp->swap);
                }
        }
}

#endif  /* BOOT_FW_DHCP */

void
ofw_getbootinfo(char **bp_pp, char **ba_pp)
{
        int chosen;
        int bp_len;
        int ba_len;
        char *bootpathv;
        char *bootargsv;

        /* Read the bootpath and bootargs out of OFW. */
        /* XXX is bootpath still interesting?  --emg */
        if ((chosen = OF_finddevice("/chosen")) == -1)
                panic("no /chosen from OFW");
        bp_len = OF_getproplen(chosen, "bootpath");
        ba_len = OF_getproplen(chosen, "bootargs");
        if (bp_len < 0 || ba_len < 0)
                panic("can't get boot data from OFW");

        bootpathv = (char *)ofw_malloc(bp_len);
        bootargsv = (char *)ofw_malloc(ba_len);

        if (bp_len)
                OF_getprop(chosen, "bootpath", bootpathv, bp_len);
        else
                bootpathv[0] = '\0';

        if (ba_len)
                OF_getprop(chosen, "bootargs", bootargsv, ba_len);
        else
                bootargsv[0] = '\0';

        *bp_pp = bootpathv;
        *ba_pp = bootargsv;
#ifdef DIAGNOSTIC
        printf("bootpath=<%s>, bootargs=<%s>\n", bootpathv, bootargsv);
#endif
}

paddr_t
ofw_getcleaninfo(void)
{
        int cpu;
        vaddr_t vclean;
        paddr_t pclean;

        if ((cpu = OF_finddevice("/cpu")) == -1)
                panic("no /cpu from OFW");

        if ((OF_getprop(cpu, "d-cache-flush-address", &vclean, 
            sizeof(vclean))) != sizeof(vclean)) {
#ifdef DEBUG
                printf("no OFW d-cache-flush-address property\n");
#endif
                return -1;
        }

        if ((pclean = ofw_gettranslation(
            of_decode_int((unsigned char *)&vclean))) == -1)
        panic("OFW failed to translate cache flush address");

        return pclean;
}

void
ofw_configisa(paddr_t *pio, paddr_t *pmem)
{
        int vl;

        if ((vl = OF_finddevice("/vlbus")) == -1) /* old style OFW dev info tree */
                ofw_configisaonly(pio, pmem);
        else /* old style OFW dev info tree */
                ofw_configvl(vl, pio, pmem);
}

static void
ofw_configisaonly(paddr_t *pio, paddr_t *pmem)
{
        int isa;
        int rangeidx;
        int size;
        paddr_t hi, start;
        struct isa_range ranges[2];
  
        if ((isa = OF_finddevice("/isa")) == -1)
        panic("OFW has no /isa device node");

        /* expect to find two isa ranges: IO/data and memory/data */
        if ((size = OF_getprop(isa, "ranges", ranges, sizeof(ranges))) 
            != sizeof(ranges))
                panic("unexpected size of OFW /isa ranges property: %d", size);

        *pio = *pmem = -1;

        for (rangeidx = 0; rangeidx < 2; ++rangeidx) {
                hi    = of_decode_int((unsigned char *)
                    &ranges[rangeidx].isa_phys_hi);
                start = of_decode_int((unsigned char *)
                    &ranges[rangeidx].parent_phys_start);

        if (hi & 1) { /* then I/O space */
                *pio = start;
        } else {
                *pmem = start;
        }
        } /* END for */

        if ((*pio == -1) || (*pmem == -1))
                panic("bad OFW /isa ranges property");

}

static void
ofw_configvl(int vl, paddr_t *pio, paddr_t *pmem)
{
        int isa;
        int ir, vr;
        int size;
        paddr_t hi, start;
        struct vl_isa_range isa_ranges[2];
        struct vl_range     vl_ranges[2];
  
        if ((isa = OF_finddevice("/vlbus/isa")) == -1)
                panic("OFW has no /vlbus/isa device node");

        /* expect to find two isa ranges: IO/data and memory/data */
        if ((size = OF_getprop(isa, "ranges", isa_ranges, sizeof(isa_ranges))) 
            != sizeof(isa_ranges))
                panic("unexpected size of OFW /vlbus/isa ranges property: %d",
                     size);

        /* expect to find two vl ranges: IO/data and memory/data */
        if ((size = OF_getprop(vl, "ranges", vl_ranges, sizeof(vl_ranges))) 
            != sizeof(vl_ranges))
                panic("unexpected size of OFW /vlbus ranges property: %d", size);

        *pio = -1;
        *pmem = -1;

        for (ir = 0; ir < 2; ++ir) {
                for (vr = 0; vr < 2; ++vr) {
                        if ((isa_ranges[ir].parent_phys_hi
                            == vl_ranges[vr].vl_phys_hi) &&
                            (isa_ranges[ir].parent_phys_lo
                            == vl_ranges[vr].vl_phys_lo)) {
                                hi    = of_decode_int((unsigned char *)
                                    &isa_ranges[ir].isa_phys_hi);
                                start = of_decode_int((unsigned char *)
                                    &vl_ranges[vr].parent_phys_start);

                                if (hi & 1) { /* then I/O space */
                                        *pio = start;
                                } else {
                                        *pmem = start;
                                }
                        } /* END if */
                } /* END for */
        } /* END for */

        if ((*pio == -1) || (*pmem == -1))
                panic("bad OFW /isa ranges property");
}

#if NISADMA > 0
struct arm32_dma_range *shark_isa_dma_ranges;
int shark_isa_dma_nranges;
#endif

void
ofw_configisadma(paddr_t *pdma)
{
        int root;
        int rangeidx;
        int size;
        struct dma_range *dr;

        if ((root = OF_finddevice("/")) == -1 ||
            (size = OF_getproplen(root, "dma-ranges")) <= 0 ||
            (OFdmaranges = (struct dma_range *)ofw_malloc(size)) == 0 ||
            OF_getprop(root, "dma-ranges", OFdmaranges, size) != size)
                panic("bad / dma-ranges property");

        nOFdmaranges = size / sizeof(struct dma_range);

#if NISADMA > 0
        /* Allocate storage for non-OFW representation of the range. */
        shark_isa_dma_ranges = ofw_malloc(nOFdmaranges *
            sizeof(*shark_isa_dma_ranges));
        if (shark_isa_dma_ranges == NULL)
                panic("unable to allocate shark_isa_dma_ranges");
        shark_isa_dma_nranges = nOFdmaranges;
#endif

        for (rangeidx = 0, dr = OFdmaranges; rangeidx < nOFdmaranges;
            ++rangeidx, ++dr) {
                dr->start = of_decode_int((unsigned char *)&dr->start);
                dr->size = of_decode_int((unsigned char *)&dr->size);
#if NISADMA > 0
                shark_isa_dma_ranges[rangeidx].dr_sysbase = dr->start;
                shark_isa_dma_ranges[rangeidx].dr_busbase = dr->start;
                shark_isa_dma_ranges[rangeidx].dr_len  = dr->size;
#endif
        }

#ifdef DEBUG
        printf("DMA ranges size = %d\n", size);

        for (rangeidx = 0; rangeidx < nOFdmaranges; ++rangeidx) {
                printf("%08lx %08lx\n", 
                (u_long)OFdmaranges[rangeidx].start, 
                (u_long)OFdmaranges[rangeidx].size);
        }
#endif
}

/* 
 *  Memory configuration:
 *
 *  We start off running in the environment provided by OFW.
 *  This has the MMU turned on, the kernel code and data
 *  mapped-in at KERNEL_BASE (0xF0000000), OFW's text and
 *  data mapped-in at OFW_VIRT_BASE (0xF7000000), and (possibly)
 *  page0 mapped-in at 0x0.
 *
 *  The strategy is to set-up the address space for proc0 --
 *  including the allocation of space for new page tables -- while
 *  memory is still managed by OFW.  We then effectively create a
 *  copy of the address space by dumping all of OFW's translations
 *  and poking them into the new page tables.  We then notify OFW
 *  that we are assuming control of memory-management by installing
 *  our callback-handler, and switch to the NetBSD-managed page
 *  tables with the cpu_setttb() call.
 *  
 *  This scheme may cause some amount of memory to be wasted within
 *  OFW as dead page tables, but it shouldn't be more than about 
 *  20-30KB.  (It's also possible that OFW will re-use the space.)
 */
void
ofw_configmem(void)
{
        int i;

        /* Set-up proc0 address space. */
        ofw_construct_proc0_addrspace();

        /*
         * Get a dump of OFW's picture of physical memory.
         * This is used below to initialize a load of variables used by pmap.
         * We get it now rather than later because we are about to
         * tell OFW to stop managing memory.
         */
        ofw_getphysmeminfo();

        /* We are about to take control of memory-management from OFW.
         * Establish callbacks for OFW to use for its future memory needs.
         * This is required for us to keep using OFW services.
         */

        /* First initialize our callback memory allocator. */
        ofw_initallocator();

        OF_set_callback(ofw_callbackhandler);

        /* Switch to the proc0 pagetables. */
        cpu_domains((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT);
        cpu_setttb(kernel_l1pt.pv_pa, true);
        cpu_tlb_flushID();
        cpu_domains(DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2));

        /*
         * Moved from cpu_startup() as data_abort_handler() references
         * this during uvm init
         */
        uvm_lwp_setuarea(&lwp0, kernelstack.pv_va);

        /* Set-up the various globals which describe physical memory for pmap. */
        {
                struct mem_region *mp;
                int totalcnt;
                int availcnt;

                /* physmem, physical_start, physical_end */
                physmem = 0;
                for (totalcnt = 0, mp = OFphysmem; totalcnt < nOFphysmem;
                    totalcnt++, mp++) {
#ifdef  OLDPRINTFS
                        printf("physmem: %lx, %lx\n", mp->start, mp->size);
#endif
                        physmem += btoc(mp->size);
                }
                physical_start = OFphysmem[0].start;
                mp--;
                physical_end = mp->start + mp->size;

                /* free_pages, physical_freestart, physical_freeend */
                free_pages = 0;
                for (availcnt = 0, mp = OFphysavail; availcnt < nOFphysavail;
                    availcnt++, mp++) {
#ifdef  OLDPRINTFS
                        printf("physavail: %lx, %lx\n", mp->start, mp->size);
#endif
                        free_pages += btoc(mp->size);
                }
                physical_freestart = OFphysavail[0].start;
                mp--;
                physical_freeend = mp->start + mp->size;
#ifdef  OLDPRINTFS
                printf("pmap_bootstrap:  physmem = %lx, free_pages = %x\n",
                    physmem, free_pages);
#endif

                /*
                 *  This is a hack to work with the existing pmap code.
                 *  That code depends on a RiscPC BootConfig structure
                 *  containing, among other things, an array describing
                 *  the regions of physical memory.  So, for now, we need
                 *  to stuff our OFW-derived physical memory info into a
                 *  "fake" BootConfig structure.
                 *
                 *  An added twist is that we initialize the BootConfig
                 *  structure with our "available" physical memory regions
                 *  rather than the "total" physical memory regions.  Why?
                 *  Because:
                 *
                 *   (a) the VM code requires that the "free" pages it is
                 *       initialized with have consecutive indices.  This
                 *       allows it to use more efficient data structures
                 *       (presumably).
                 *   (b) the current pmap routines which report the initial
                 *       set of free page indices (pmap_next_page) and
                 *       which map addresses to indices (pmap_page_index)
                 *       assume that the free pages are consecutive across
                 *       memory region boundaries.
                 *
                 *  This means that memory which is "stolen" at startup time
                 *  (say, for page descriptors) MUST come from either the
                 *  bottom of the first region or the top of the last.
                 *
                 *  This requirement doesn't mesh well with OFW (or at least
                 *  our use of it).  We can get around it for the time being
                 *  by pretending that our "available" region array describes
                 *  all of our physical memory.  This may cause some important
                 *  information to be excluded from a dump file, but so far
                 *  I haven't come across any other negative effects.
                 *
                 *  In the long-run we should fix the index
                 *  generation/translation code in the pmap module.
                 */

                if (DRAM_BLOCKS < (availcnt + 1))
                        panic("more ofw memory regions than bootconfig blocks");

                for (i = 0, mp = OFphysavail; i < nOFphysavail; i++, mp++) {
                        bootconfig.dram[i].address = mp->start;
                        bootconfig.dram[i].pages = btoc(mp->size);
                }
                bootconfig.dramblocks = availcnt;
        }

        uvm_md_init();

        /* XXX Please kill this code dead. */
        for (i = 0; i < bootconfig.dramblocks; i++) {
                paddr_t start = (paddr_t)bootconfig.dram[i].address;
                paddr_t end = start + (bootconfig.dram[i].pages * PAGE_SIZE);
#if NISADMA > 0
                paddr_t istart, isize;
#endif

                if (start < physical_freestart)
                        start = physical_freestart;
                if (end > physical_freeend)
                        end = physical_freeend;

#if 0
                printf("%d: %lx -> %lx\n", loop, start, end - 1);
#endif

#if NISADMA > 0
                if (arm32_dma_range_intersect(shark_isa_dma_ranges,
                                              shark_isa_dma_nranges,
                                              start, end - start,
                                              &istart, &isize)) {
                        /*
                         * Place the pages that intersect with the
                         * ISA DMA range onto the ISA DMA free list.
                         */
#if 0
                        printf("    ISADMA 0x%lx -> 0x%lx\n", istart,
                            istart + isize - 1);
#endif
                        uvm_page_physload(atop(istart),
                            atop(istart + isize), atop(istart),
                            atop(istart + isize), VM_FREELIST_ISADMA);

                        /*
                         * Load the pieces that come before the
                         * intersection onto the default free list.
                         */
                        if (start < istart) {
#if 0
                                printf("    BEFORE 0x%lx -> 0x%lx\n",
                                    start, istart - 1);
#endif
                                uvm_page_physload(atop(start),
                                    atop(istart), atop(start),
                                    atop(istart), VM_FREELIST_DEFAULT);
                        }

                        /*
                         * Load the pieces that come after the
                         * intersection onto the default free list.
                         */
                        if ((istart + isize) < end) {
#if 0
                                printf("     AFTER 0x%lx -> 0x%lx\n",
                                    (istart + isize), end - 1);
#endif
                                uvm_page_physload(atop(istart + isize),
                                    atop(end), atop(istart + isize),
                                    atop(end), VM_FREELIST_DEFAULT);
                        }
                } else {
                        uvm_page_physload(atop(start), atop(end),
                            atop(start), atop(end), VM_FREELIST_DEFAULT);
                }
#else /* NISADMA > 0 */
                uvm_page_physload(atop(start), atop(end),
                    atop(start), atop(end), VM_FREELIST_DEFAULT);
#endif /* NISADMA > 0 */
        }

        /* Initialize pmap module. */
        pmap_bootstrap(KERNEL_VM_BASE, KERNEL_VM_BASE + KERNEL_VM_SIZE);
}


/*
 ************************************************************

  Routines private to this module

 ************************************************************
 */

/* N.B.  Not supposed to call printf in callback-handler!  Could deadlock! */
static void
ofw_callbackhandler(void *v)
{
        struct ofw_cbargs *args = v;
        char *name = args->name;
        int nargs = args->nargs;
        int nreturns = args->nreturns;
        int *args_n_results = args->args_n_results;

        ofw_callbacks++;

#if defined(OFWGENCFG)
        /* Check this first, so that we don't waste IRQ time parsing. */
        if (strcmp(name, "tick") == 0) {
                vaddr_t frame;

                /* Check format. */
                if (nargs != 1 || nreturns < 1) {
                        args_n_results[nargs] = -1;
                        args->nreturns = 1;
                        return;
                }
                args_n_results[nargs] = 0;      /* properly formatted request */

                /*
                 *  Note that we are running in the IRQ frame, with interrupts
                 *  disabled.
                 *  
                 *  We need to do two things here:
                 *    - copy a few words out of the input frame into a global
                 *      area, for later use by our real tick-handling code
                 *    - patch a few words in the frame so that when OFW returns
                 *      from the interrupt it will resume with our handler
                 *      rather than the code that was actually interrupted.
                 *      Our handler will resume when it finishes with the code
                 *      that was actually interrupted.
                 *  
                 *  It's simplest to do this in assembler, since it requires
                 *  switching frames and grovelling about with registers.
                 */
                frame = (vaddr_t)args_n_results[0];
                if (ofw_handleticks)
                        dotickgrovelling(frame);
                args_n_results[nargs + 1] = frame;
                args->nreturns = 1;
        } else
#endif

        if (strcmp(name, "map") == 0) {
                vaddr_t va;
                paddr_t pa;
                vsize_t size;
                int mode;
                int ap_bits;
                int dom_bits;
                int cb_bits;

                /* Check format. */
                if (nargs != 4 || nreturns < 2) {
                        args_n_results[nargs] = -1;
                        args->nreturns = 1;
                        return;
                }
                args_n_results[nargs] = 0;      /* properly formatted request */

                pa = (paddr_t)args_n_results[0];
                va = (vaddr_t)args_n_results[1];
                size = (vsize_t)args_n_results[2];
                mode = args_n_results[3];
                ap_bits =  (mode & 0x00000C00);
                dom_bits = (mode & 0x000001E0);
                cb_bits =  (mode & 0x000000C0);

                /* Sanity checks. */
                if ((va & PGOFSET) != 0 || va < OFW_VIRT_BASE ||
                    (va + size) > (OFW_VIRT_BASE + OFW_VIRT_SIZE) ||
                    (pa & PGOFSET) != 0 || (size & PGOFSET) != 0 ||
                    size == 0 || (dom_bits >> 5) != 0) {
                        args_n_results[nargs + 1] = -1;
                        args->nreturns = 1;
                        return;
                }

                /* Write-back anything stuck in the cache. */
                cpu_idcache_wbinv_all();

                /* Install new mappings. */
                {
                        pt_entry_t *ptep = vtopte(va);
                        KASSERT(ptep + size / L2_S_SIZE == vtopte(va + size));
                        pt_entry_t npte = pa | L2_TYPE_S | L2_AP(ap_bits)
                            | cb_bits;
                        
                        ap_bits >>= 10;
                        for (size_t npages = size >> PGSHIFT;
                             npages-- > 0;
                             ptep += PAGE_SIZE / L2_S_SIZE, npte += PAGE_SIZE) {
                                l2pte_set(ptep, npte, 0);
                        }
                        PTE_SYNC_RANGE(vtopte(va), size >> L2_S_SHIFT);
                }

                /* Clean out tlb. */
                cpu_tlb_flushID();

                args_n_results[nargs + 1] = 0;
                args->nreturns = 2;
        } else if (strcmp(name, "unmap") == 0) {
                vaddr_t va;
                vsize_t size;

                /* Check format. */
                if (nargs != 2 || nreturns < 1) {
                        args_n_results[nargs] = -1;
                        args->nreturns = 1;
                        return;
                }
                args_n_results[nargs] = 0;      /* properly formatted request */

                va = (vaddr_t)args_n_results[0];
                size = (vsize_t)args_n_results[1];

                /* Sanity checks. */
                if ((va & PGOFSET) != 0 || va < OFW_VIRT_BASE ||
                    (va + size) > (OFW_VIRT_BASE + OFW_VIRT_SIZE) ||
                    (size & PGOFSET) != 0 || size == 0) {
                        args_n_results[nargs + 1] = -1;
                        args->nreturns = 1;
                        return;
                }

                /* Write-back anything stuck in the cache. */
                cpu_idcache_wbinv_all();

                /* Zero the mappings. */
                {
                        pt_entry_t *ptep = vtopte(va);
                        
                        for (size_t npages = size >> PGSHIFT;
                             npages-- > 0;
                             ptep += PAGE_SIZE / L2_S_SIZE) {
                                l2pte_reset(ptep);
                        }
                        PTE_SYNC_RANGE(vtopte(va), size >> L2_S_SHIFT);
                }

                /* Clean out tlb. */
                cpu_tlb_flushID();

                args->nreturns = 1;
        } else if (strcmp(name, "translate") == 0) {
                vaddr_t va;
                paddr_t pa;
                int mode;
                pt_entry_t pte;

                /* Check format. */
                if (nargs != 1 || nreturns < 4) {
                        args_n_results[nargs] = -1;
                        args->nreturns = 1;
                        return;
                }
                args_n_results[nargs] = 0;      /* properly formatted request */

                va = (vaddr_t)args_n_results[0];

                /* Sanity checks.
                 * For now, I am only willing to translate va's in the
                 * "ofw range." Eventually, I may be more generous. -JJK
                 */
                if ((va & PGOFSET) != 0 ||  va < OFW_VIRT_BASE ||
                    va >= (OFW_VIRT_BASE + OFW_VIRT_SIZE)) {
                        args_n_results[nargs + 1] = -1;
                        args->nreturns = 1;
                        return;
                }

                /* Lookup mapping. */
                pte = *vtopte(va);
                if (pte == 0) {
                        /* No mapping. */
                        args_n_results[nargs + 1] = -1;
                        args->nreturns = 2;
                } else {
                        /* Existing mapping. */
                        pa = (pte & L2_S_FRAME) | (va & L2_S_OFFSET);
                        mode = (pte & 0x0C00) | (0 << 5) | (pte & 0x000C);      /* AP | DOM | CB */

                        args_n_results[nargs + 1] = 0;
                        args_n_results[nargs + 2] = pa;
                        args_n_results[nargs + 3] =     mode;
                        args->nreturns = 4;
                }
        } else if (strcmp(name, "claim-phys") == 0) {
                struct pglist alloclist;
                paddr_t low, high, align;
                psize_t size;

                /*
                 * XXX
                 * XXX THIS IS A GROSS HACK AND NEEDS TO BE REWRITTEN. -- cgd
                 * XXX
                 */

                /* Check format. */
                if (nargs != 4 || nreturns < 3) {
                        args_n_results[nargs] = -1;
                        args->nreturns = 1;
                        return;
                }
                args_n_results[nargs] = 0;      /* properly formatted request */

                low = args_n_results[0];
                size = args_n_results[2];
                align = args_n_results[3];
                high = args_n_results[1] + size;

#if 0
                printf("claim-phys: low = 0x%x, size = 0x%x, align = 0x%x, high = 0x%x\n",
                    low, size, align, high);
                align = size;
                printf("forcing align to be 0x%x\n", align);
#endif

                args_n_results[nargs + 1] =
                uvm_pglistalloc(size, low, high, align, 0, &alloclist, 1, 0);
#if 0
                printf(" -> 0x%lx", args_n_results[nargs + 1]);
#endif
                if (args_n_results[nargs + 1] != 0) {
#if 0
                        printf("(failed)\n");
#endif
                        args_n_results[nargs + 1] = -1;
                        args->nreturns = 2;
                        return;
                } 
                args_n_results[nargs + 2] = VM_PAGE_TO_PHYS(alloclist.tqh_first);
#if 0
                printf("(succeeded: pa = 0x%lx)\n", args_n_results[nargs + 2]);
#endif
                args->nreturns = 3;

        } else if (strcmp(name, "release-phys") == 0) {
                printf("unimplemented ofw callback - %s\n", name);
                args_n_results[nargs] = -1;
                args->nreturns = 1;
        } else if (strcmp(name, "claim-virt") == 0) {
                vaddr_t va;
                vaddr_t align;

                /* XXX - notyet */
/*              printf("unimplemented ofw callback - %s\n", name);*/
                args_n_results[nargs] = -1;
                args->nreturns = 1;
                return;

                /* Check format. */
                if (nargs != 2 || nreturns < 3) {
                    args_n_results[nargs] = -1;
                    args->nreturns = 1;
                    return;
                }
                args_n_results[nargs] = 0;      /* properly formatted request */

                /* Allocate size bytes with specified alignment. */
                align = (vaddr_t)args_n_results[1];
                if (align % PAGE_SIZE != 0) {
                        args_n_results[nargs + 1] = -1;
                        args->nreturns = 2;
                        return;
                }

                if (va == 0) {
                        /* Couldn't allocate. */
                        args_n_results[nargs + 1] = -1;
                        args->nreturns = 2;
                } else {
                        /* Successful allocation. */
                        args_n_results[nargs + 1] = 0;
                        args_n_results[nargs + 2] = va;
                        args->nreturns = 3;
                }
        } else if (strcmp(name, "release-virt") == 0) {

                /* XXX - notyet */
                printf("unimplemented ofw callback - %s\n", name);
                args_n_results[nargs] = -1;
                args->nreturns = 1;
                return;

                /* Check format. */
                if (nargs != 2 || nreturns < 1) {
                        args_n_results[nargs] = -1;
                        args->nreturns = 1;
                        return;
                }
                args_n_results[nargs] = 0;      /* properly formatted request */

                args->nreturns = 1;
        } else {
                args_n_results[nargs] = -1;
                args->nreturns = 1;
        }
}

static void
ofw_construct_proc0_addrspace(void)
{
        int i, oft;
        static pv_addr_t proc0_pt_sys;
        static pv_addr_t proc0_pt_kernel[KERNEL_IMG_PTS];
        static pv_addr_t proc0_pt_vmdata[KERNEL_VMDATA_PTS];
        static pv_addr_t proc0_pt_ofw[KERNEL_OFW_PTS];
        static pv_addr_t proc0_pt_io[KERNEL_IO_PTS];
        static pv_addr_t msgbuf;
        vaddr_t L1pagetable;
        struct mem_translation *tp;

        /* Set-up the system page. */
        KASSERT(vector_page == 0);      /* XXX for now */
        systempage.pv_va = ofw_claimvirt(vector_page, PAGE_SIZE, 0);
        if (systempage.pv_va == -1) {
                /* Something was already mapped to vector_page's VA. */
                systempage.pv_va = vector_page;
                systempage.pv_pa = ofw_gettranslation(vector_page);
                if (systempage.pv_pa == -1)
                        panic("bogus result from gettranslation(vector_page)");
        } else {
                /* We were just allocated the page-length range at VA 0. */
                if (systempage.pv_va != vector_page)
                        panic("bogus result from claimvirt(vector_page, PAGE_SIZE, 0)");

                /* Now allocate a physical page, and establish the mapping. */
                systempage.pv_pa = ofw_claimphys(0, PAGE_SIZE, PAGE_SIZE);
                if (systempage.pv_pa == -1)
                        panic("bogus result from claimphys(0, PAGE_SIZE, PAGE_SIZE)");
                ofw_settranslation(systempage.pv_va, systempage.pv_pa,
                    PAGE_SIZE, -1);     /* XXX - mode? -JJK */

                /* Zero the memory. */
                memset((char *)systempage.pv_va, 0, PAGE_SIZE);
        }

        /* Allocate/initialize space for the proc0, NetBSD-managed */
        /* page tables that we will be switching to soon. */
        ofw_claimpages(&virt_freeptr, &kernel_l1pt, L1_TABLE_SIZE);
        ofw_claimpages(&virt_freeptr, &proc0_pt_sys, L2_TABLE_SIZE);
        for (i = 0; i < KERNEL_IMG_PTS; i++)
                ofw_claimpages(&virt_freeptr, &proc0_pt_kernel[i], L2_TABLE_SIZE);
        for (i = 0; i < KERNEL_VMDATA_PTS; i++)
                ofw_claimpages(&virt_freeptr, &proc0_pt_vmdata[i], L2_TABLE_SIZE);
        for (i = 0; i < KERNEL_OFW_PTS; i++)
                ofw_claimpages(&virt_freeptr, &proc0_pt_ofw[i], L2_TABLE_SIZE);
        for (i = 0; i < KERNEL_IO_PTS; i++)
                ofw_claimpages(&virt_freeptr, &proc0_pt_io[i], L2_TABLE_SIZE);

        /* Allocate/initialize space for stacks. */
#ifndef OFWGENCFG
        ofw_claimpages(&virt_freeptr, &irqstack, PAGE_SIZE);
#endif
        ofw_claimpages(&virt_freeptr, &undstack, PAGE_SIZE);
        ofw_claimpages(&virt_freeptr, &abtstack, PAGE_SIZE);
        ofw_claimpages(&virt_freeptr, &kernelstack, UPAGES * PAGE_SIZE);

        /* Allocate/initialize space for msgbuf area. */
        ofw_claimpages(&virt_freeptr, &msgbuf, MSGBUFSIZE);
        msgbufphys = msgbuf.pv_pa;

        /* Construct the proc0 L1 pagetable. */
        L1pagetable = kernel_l1pt.pv_va;

        pmap_link_l2pt(L1pagetable, 0x0, &proc0_pt_sys);
        for (i = 0; i < KERNEL_IMG_PTS; i++)
                pmap_link_l2pt(L1pagetable, KERNEL_BASE + i * 0x00400000,
                    &proc0_pt_kernel[i]);
        for (i = 0; i < KERNEL_VMDATA_PTS; i++)
                pmap_link_l2pt(L1pagetable, KERNEL_VM_BASE + i * 0x00400000,
                    &proc0_pt_vmdata[i]);
        for (i = 0; i < KERNEL_OFW_PTS; i++)
                pmap_link_l2pt(L1pagetable, OFW_VIRT_BASE + i * 0x00400000,
                    &proc0_pt_ofw[i]);
        for (i = 0; i < KERNEL_IO_PTS; i++)
                pmap_link_l2pt(L1pagetable, IO_VIRT_BASE + i * 0x00400000,
                    &proc0_pt_io[i]);

        /*
         * OK, we're done allocating.
         * Get a dump of OFW's translations, and make the appropriate
         * entries in the L2 pagetables that we just allocated.
         */

        ofw_getvirttranslations();

        for (oft = 0,  tp = OFtranslations; oft < nOFtranslations;
            oft++, tp++) {

                vaddr_t va;
                paddr_t pa;
                int npages = tp->size / PAGE_SIZE;

                /* Size must be an integral number of pages. */
                if (npages == 0 || tp->size % PAGE_SIZE != 0)
                        panic("illegal ofw translation (size)");

                /* Make an entry for each page in the appropriate table. */
                for (va = tp->virt, pa = tp->phys; npages > 0;
                    va += PAGE_SIZE, pa += PAGE_SIZE, npages--) {
                        /*
                         * Map the top bits to the appropriate L2 pagetable.
                         * The only allowable regions are page0, the
                         * kernel-static area, and the ofw area.
                         */
                        switch (va >> (L1_S_SHIFT + 2)) {
                        case 0:
                                /* page0 */
                                break;

#if KERNEL_IMG_PTS != 2
#error "Update ofw translation range list"
#endif
                        case ( KERNEL_BASE                 >> (L1_S_SHIFT + 2)):
                        case ((KERNEL_BASE   + 0x00400000) >> (L1_S_SHIFT + 2)):
                                /* kernel static area */
                                break;

                        case ( OFW_VIRT_BASE               >> (L1_S_SHIFT + 2)):
                        case ((OFW_VIRT_BASE + 0x00400000) >> (L1_S_SHIFT + 2)):
                        case ((OFW_VIRT_BASE + 0x00800000) >> (L1_S_SHIFT + 2)):
                        case ((OFW_VIRT_BASE + 0x00C00000) >> (L1_S_SHIFT + 2)):
                                /* ofw area */
                                break;

                        case ( IO_VIRT_BASE               >> (L1_S_SHIFT + 2)):
                        case ((IO_VIRT_BASE + 0x00400000) >> (L1_S_SHIFT + 2)):
                        case ((IO_VIRT_BASE + 0x00800000) >> (L1_S_SHIFT + 2)):
                        case ((IO_VIRT_BASE + 0x00C00000) >> (L1_S_SHIFT + 2)):
                                /* io area */
                                break;

                        default:
                                /* illegal */
                                panic("illegal ofw translation (addr) %#lx",
                                    va);
                        }

                        /* Make the entry. */
                        pmap_map_entry(L1pagetable, va, pa,
                            VM_PROT_READ|VM_PROT_WRITE,
                            (tp->mode & 0xC) == 0xC ? PTE_CACHE
                                                    : PTE_NOCACHE);
                }
        }

        /*
         * We don't actually want some of the mappings that we just
         * set up to appear in proc0's address space.  In particular,
         * we don't want aliases to physical addresses that the kernel
         * has-mapped/will-map elsewhere.
         */
        ofw_discardmappings(proc0_pt_kernel[KERNEL_IMG_PTS - 1].pv_va,
            msgbuf.pv_va, MSGBUFSIZE);

        /* update the top of the kernel VM */
        pmap_curmaxkvaddr =
            KERNEL_VM_BASE + (KERNEL_VMDATA_PTS * 0x00400000);
        
        /* 
         * gross hack for the sake of not thrashing the TLB and making
         * cache flush more efficient: blast l1 ptes for sections.
         */
        for (oft = 0, tp = OFtranslations; oft < nOFtranslations; oft++, tp++) {
                vaddr_t va = tp->virt;
                paddr_t pa = tp->phys;

                if (((va | pa) & L1_S_OFFSET) == 0) {
                        int nsections = tp->size / L1_S_SIZE;

                        while (nsections--) {
                                /* XXXJRT prot?? */
                                pmap_map_section(L1pagetable, va, pa,
                                    VM_PROT_READ|VM_PROT_WRITE,
                                    (tp->mode & 0xC) == 0xC ? PTE_CACHE
                                                            : PTE_NOCACHE);
                                va += L1_S_SIZE;
                                pa += L1_S_SIZE;
                        }
                }
        }
}


static void
ofw_getphysmeminfo(void)
{
        int phandle;
        int mem_len;
        int avail_len;
        int i;

        if ((phandle = OF_finddevice("/memory")) == -1 ||
            (mem_len = OF_getproplen(phandle, "reg")) <= 0 ||
            (OFphysmem = (struct mem_region *)ofw_malloc(mem_len)) == 0 ||
            OF_getprop(phandle, "reg", OFphysmem, mem_len) != mem_len ||
            (avail_len = OF_getproplen(phandle, "available")) <= 0 ||
            (OFphysavail = (struct mem_region *)ofw_malloc(avail_len)) == 0 ||
            OF_getprop(phandle, "available", OFphysavail, avail_len)
            != avail_len)
                panic("can't get physmeminfo from OFW");

        nOFphysmem = mem_len / sizeof(struct mem_region);
        nOFphysavail = avail_len / sizeof(struct mem_region);

        /*
         * Sort the blocks in each array into ascending address order.
         * Also, page-align all blocks.
         */
        for (i = 0; i < 2; i++) {
                struct mem_region *tmp = (i == 0) ? OFphysmem : OFphysavail;
                struct mem_region *mp;
                int cnt =  (i == 0) ? nOFphysmem : nOFphysavail;
                int j;

#ifdef  OLDPRINTFS
                printf("ofw_getphysmeminfo:  %d blocks\n", cnt);
#endif

                /* XXX - Convert all the values to host order. -JJK */
                for (j = 0, mp = tmp; j < cnt; j++, mp++) {
                        mp->start = of_decode_int((unsigned char *)&mp->start);
                        mp->size = of_decode_int((unsigned char *)&mp->size);
                }

                for (j = 0, mp = tmp; j < cnt; j++, mp++) {
                        u_int s, sz;
                        struct mem_region *mp1;

                        /* Page-align start of the block. */
                        s = mp->start % PAGE_SIZE;
                        if (s != 0) {
                                s = (PAGE_SIZE - s);

                                if (mp->size >= s) {
                                        mp->start += s;
                                        mp->size -= s;
                                }
                        }

                        /* Page-align the size. */
                        mp->size -= mp->size % PAGE_SIZE;

                        /* Handle empty block. */
                        if (mp->size == 0) {
                                memmove(mp, mp + 1, (cnt - (mp - tmp))
                                    * sizeof(struct mem_region));
                                cnt--;
                                mp--;
                                continue;
                        }

                        /* Bubble sort. */
                        s = mp->start;
                        sz = mp->size;
                        for (mp1 = tmp; mp1 < mp; mp1++)
                                if (s < mp1->start)
                                        break;
                        if (mp1 < mp) {
                                memmove(mp1 + 1, mp1, (char *)mp - (char *)mp1);
                                mp1->start = s;
                                mp1->size = sz;
                        }
                }

#ifdef  OLDPRINTFS
                for (mp = tmp; mp->size; mp++) {
                        printf("%lx, %lx\n", mp->start, mp->size);
                }
#endif
        }
}


static void
ofw_getvirttranslations(void)
{
        int mmu_phandle;
        int mmu_ihandle;
        int trans_len;
        int over, len;
        int i;
        struct mem_translation *tp;

        mmu_ihandle = ofw_mmu_ihandle();

        /* overallocate to avoid increases during allocation */
        over = 4 * sizeof(struct mem_translation);
        if ((mmu_phandle = OF_instance_to_package(mmu_ihandle)) == -1 ||
            (len = OF_getproplen(mmu_phandle, "translations")) <= 0 ||
            (OFtranslations = ofw_malloc(len + over)) == 0 ||
            (trans_len = OF_getprop(mmu_phandle, "translations",
            OFtranslations, len + over)) > (len + over))
                panic("can't get virttranslations from OFW");

        /* XXX - Convert all the values to host order. -JJK */
        nOFtranslations = trans_len / sizeof(struct mem_translation);
#ifdef  OLDPRINTFS
        printf("ofw_getvirtmeminfo:  %d blocks\n", nOFtranslations);
#endif
        for (i = 0, tp = OFtranslations; i < nOFtranslations; i++, tp++) {
                tp->virt = of_decode_int((unsigned char *)&tp->virt);
                tp->size = of_decode_int((unsigned char *)&tp->size);
                tp->phys = of_decode_int((unsigned char *)&tp->phys);
                tp->mode = of_decode_int((unsigned char *)&tp->mode);
        }
}

/*
 * ofw_valloc: allocate blocks of VM for IO and other special purposes
 */
typedef struct _vfree {
        struct _vfree *pNext;
        vaddr_t start;
        vsize_t size;
} VFREE, *PVFREE;

static VFREE vfinitial = { NULL, IO_VIRT_BASE, IO_VIRT_SIZE };

static PVFREE vflist = &vfinitial;

static vaddr_t
ofw_valloc(vsize_t size, vaddr_t align)
{
        PVFREE        *ppvf;
        PVFREE        pNew;
        vaddr_t       new;
        vaddr_t       lead;

        for (ppvf = &vflist; *ppvf; ppvf = &((*ppvf)->pNext)) {
                if (align == 0) {
                        new = (*ppvf)->start;
                        lead = 0;
                } else {
                        new  = ((*ppvf)->start + (align - 1)) & ~(align - 1);
                        lead = new - (*ppvf)->start;
                }

                if (((*ppvf)->size - lead) >= size) {
                        if (lead == 0) {
                                /* using whole block */
                                if (size == (*ppvf)->size) { 
                                        /* splice out of list */
                                        (*ppvf) = (*ppvf)->pNext;
                                } else { /* tail of block is free */
                                        (*ppvf)->start = new + size;
                                        (*ppvf)->size -= size;
                                }
                        } else {
                                vsize_t tail = ((*ppvf)->start
                                    + (*ppvf)->size) - (new + size);
                                /* free space at beginning */
                                (*ppvf)->size = lead;

                                if (tail != 0) {
                                        /* free space at tail */
                                        pNew = ofw_malloc(sizeof(VFREE));
                                        pNew->pNext  = (*ppvf)->pNext;
                                        (*ppvf)->pNext = pNew;
                                        pNew->start  = new + size;
                                        pNew->size   = tail;
                                }
                        }
                        return new;
                } /* END if */
        } /* END for */

        return -1;
}

vaddr_t
ofw_map(paddr_t pa, vsize_t size, int cb_bits)
{
        vaddr_t va;

        if ((va = ofw_valloc(size, size)) == -1)
                panic("cannot alloc virtual memory for %#lx", pa);

        ofw_claimvirt(va, size, 0); /* make sure OFW knows about the memory */

        ofw_settranslation(va, pa, size, L2_AP(AP_KRW) | cb_bits);

        return va;
}

static int
ofw_mem_ihandle(void)
{
        static int mem_ihandle = 0;
        int chosen;

        if (mem_ihandle != 0)
                return(mem_ihandle);

        if ((chosen = OF_finddevice("/chosen")) == -1 ||
            OF_getprop(chosen, "memory", &mem_ihandle, sizeof(int)) < 0)
                panic("ofw_mem_ihandle");

        mem_ihandle = of_decode_int((unsigned char *)&mem_ihandle);

        return(mem_ihandle);
}


static int
ofw_mmu_ihandle(void)
{
        static int mmu_ihandle = 0;
        int chosen;

        if (mmu_ihandle != 0)
                return(mmu_ihandle);

        if ((chosen = OF_finddevice("/chosen")) == -1 ||
            OF_getprop(chosen, "mmu", &mmu_ihandle, sizeof(int)) < 0)
                panic("ofw_mmu_ihandle");

        mmu_ihandle = of_decode_int((unsigned char *)&mmu_ihandle);

        return(mmu_ihandle);
}


/* Return -1 on failure. */
static paddr_t
ofw_claimphys(paddr_t pa, psize_t size, paddr_t align)
{
        int mem_ihandle = ofw_mem_ihandle();

/*      printf("ofw_claimphys (%x, %x, %x) --> ", pa, size, align);*/
        if (align == 0) {
                /* Allocate at specified base; alignment is ignored. */
                pa = OF_call_method_1("claim", mem_ihandle, 3, pa, size, align);
        } else {
                /* Allocate anywhere, with specified alignment. */
                pa = OF_call_method_1("claim", mem_ihandle, 2, size, align);
        }

/*      printf("%x\n", pa);*/
        return(pa);
}


#if 0
/* Return -1 on failure. */
static paddr_t
ofw_releasephys(paddr_t pa, psize_t size)
{
        int mem_ihandle = ofw_mem_ihandle();

/*      printf("ofw_releasephys (%x, %x)\n", pa, size);*/

        return (OF_call_method_1("release", mem_ihandle, 2, pa, size));
}
#endif

/* Return -1 on failure. */
static vaddr_t
ofw_claimvirt(vaddr_t va, vsize_t size, vaddr_t align)
{
        int mmu_ihandle = ofw_mmu_ihandle();

        /*printf("ofw_claimvirt (%x, %x, %x) --> ", va, size, align);*/
        if (align == 0) {
                /* Allocate at specified base; alignment is ignored. */
                va = OF_call_method_1("claim", mmu_ihandle, 3, va, size, align);
        } else {
                /* Allocate anywhere, with specified alignment. */
                va = OF_call_method_1("claim", mmu_ihandle, 2, size, align);
        }

        /*printf("%x\n", va);*/
        return(va);
}

/* Return -1 if no mapping. */
paddr_t
ofw_gettranslation(vaddr_t va)
{
        int mmu_ihandle = ofw_mmu_ihandle();
        paddr_t pa;
        int mode;
        int exists;

#ifdef OFW_DEBUG
        printf("ofw_gettranslation (%x) --> ", (uint32_t)va);
#endif
        exists = 0;         /* gets set to true if translation exists */
        if (OF_call_method("translate", mmu_ihandle, 1, 3, va, &pa, &mode,
            &exists) != 0) {
#ifdef OFW_DEBUG
                printf("(failed)\n");
#endif
                return(-1);
        }

#ifdef OFW_DEBUG
        printf("%d %x\n", exists, (uint32_t)pa);
#endif
        return(exists ? pa : -1);
}


static void
ofw_settranslation(vaddr_t va, paddr_t pa, vsize_t size, int mode)
{
        int mmu_ihandle = ofw_mmu_ihandle();

#ifdef OFW_DEBUG
        printf("ofw_settranslation (%x, %x, %x, %x) --> void\n", (uint32_t)va,
            (uint32_t)pa, (uint32_t)size, (uint32_t)mode);
#endif
        if (OF_call_method("map", mmu_ihandle, 4, 0, pa, va, size, mode) != 0)
                panic("ofw_settranslation failed");
}

/*
 *  Allocation routine used before the kernel takes over memory.
 *  Use this for efficient storage for things that aren't rounded to
 *  page size.
 *
 *  The point here is not necessarily to be very efficient (even though
 *  that's sort of nice), but to do proper dynamic allocation to avoid
 *  size-limitation errors.
 *
 */

typedef struct _leftover {
        struct _leftover *pNext;
        vsize_t size;
} LEFTOVER, *PLEFTOVER;

/* leftover bits of pages.  first word is pointer to next.
   second word is size of leftover */
static PLEFTOVER leftovers = NULL;

static void *
ofw_malloc(vsize_t size)
{
        PLEFTOVER   *ppLeftover;
        PLEFTOVER   pLeft;
        pv_addr_t   new;
        vsize_t   newSize, claim_size;

        /* round and set minimum size */
        size = uimax(sizeof(LEFTOVER), 
            ((size + (sizeof(LEFTOVER) - 1)) & ~(sizeof(LEFTOVER) - 1)));

        for (ppLeftover = &leftovers; *ppLeftover;
            ppLeftover = &((*ppLeftover)->pNext))
                if ((*ppLeftover)->size >= size)
                        break;

        if (*ppLeftover) { /* have a leftover of the right size */
                /* remember the leftover */
                new.pv_va = (vaddr_t)*ppLeftover;
                if ((*ppLeftover)->size < (size + sizeof(LEFTOVER))) {
                        /* splice out of chain */
                        *ppLeftover = (*ppLeftover)->pNext;
                } else {
                        /* remember the next pointer */
                        pLeft = (*ppLeftover)->pNext;
                        newSize = (*ppLeftover)->size - size; /* reduce size */
                        /* move pointer */
                        *ppLeftover = (PLEFTOVER)(((vaddr_t)*ppLeftover)
                            + size);
                        (*ppLeftover)->pNext = pLeft;
                        (*ppLeftover)->size  = newSize;
                }
        } else {
                claim_size = (size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
                ofw_claimpages(&virt_freeptr, &new, claim_size);
                if ((size + sizeof(LEFTOVER)) <= claim_size) {
                        pLeft = (PLEFTOVER)(new.pv_va + size);
                        pLeft->pNext = leftovers;
                        pLeft->size = claim_size - size;
                        leftovers = pLeft;
                }
        }

        return (void *)(new.pv_va);
}

/*
 *  Here is a really, really sleazy free.  It's not used right now,
 *  because it's not worth the extra complexity for just a few bytes.
 *
 */
#if 0
static void
ofw_free(vaddr_t addr, vsize_t size)
{
        PLEFTOVER pLeftover = (PLEFTOVER)addr;

        /* splice right into list without checks or compaction */
        pLeftover->pNext = leftovers;
        pLeftover->size  = size;
        leftovers        = pLeftover;
}
#endif

/*
 *  Allocate and zero round(size)/PAGE_SIZE pages of memory.
 *  We guarantee that the allocated memory will be
 *  aligned to a boundary equal to the smallest power of
 *  2 greater than or equal to size.
 *  free_pp is an IN/OUT parameter which points to the
 *  last allocated virtual address in an allocate-downwards
 *  stack.  pv_p is an OUT parameter which contains the
 *  virtual and physical base addresses of the allocated
 *  memory.
 */
static void
ofw_claimpages(vaddr_t *free_pp, pv_addr_t *pv_p, vsize_t size)
{
        /* round-up to page boundary */
        vsize_t alloc_size = (size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
        vsize_t aligned_size;
        vaddr_t va;
        paddr_t pa;

        if (alloc_size == 0)
                panic("ofw_claimpages zero");

        for (aligned_size = 1; aligned_size < alloc_size; aligned_size <<= 1)
                ;

        /*  The only way to provide the alignment guarantees is to
         *  allocate the virtual and physical ranges separately,
         *  then do an explicit map call.
         */
        va = (*free_pp & ~(aligned_size - 1)) - aligned_size;
        if (ofw_claimvirt(va, alloc_size, 0) != va)
                panic("ofw_claimpages va alloc");
        pa = ofw_claimphys(0, alloc_size, aligned_size);
        if (pa == -1)
                panic("ofw_claimpages pa alloc");
        /* XXX - what mode? -JJK */
        ofw_settranslation(va, pa, alloc_size, -1);

        /* The memory's mapped-in now, so we can zero it. */
        memset((char *)va, 0, alloc_size);

        /* Set OUT parameters. */
        *free_pp = va;
        pv_p->pv_va = va;
        pv_p->pv_pa = pa;
}


static void
ofw_discardmappings(vaddr_t L2pagetable, vaddr_t va, vsize_t size)
{
        /* round-up to page boundary */
        vsize_t alloc_size = (size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
        int npages = alloc_size / PAGE_SIZE;

        if (npages == 0)
                panic("ofw_discardmappings zero");

        /* Discard each mapping. */
        for (; npages > 0; va += PAGE_SIZE, npages--) {
                /* Sanity. The current entry should be non-null. */
                if (ReadWord(L2pagetable + ((va >> 10) & 0x00000FFC)) == 0)
                        panic("ofw_discardmappings zero entry");

                /* Clear the entry. */
                WriteWord(L2pagetable + ((va >> 10) & 0x00000FFC), 0);
        }
}


static void
ofw_initallocator(void)
{
    
}

#if (NIGSFB_OFBUS > 0) || (NCHIPSFB_OFBUS > 0) || (NVGA_OFBUS > 0)
static void
reset_screen(void)
{

        if ((console_ihandle == 0) || (console_ihandle == -1))
                return;

        OF_call_method("install", console_ihandle, 0, 0);
}
#endif /* (NIGSFB_OFBUS > 0) || (NVGA_OFBUS > 0) */