/* $NetBSD: machdep.c,v 1.7 2025/12/21 07:00:27 skrll Exp $ */

/*-
 * Copyright (c) 2001,2021 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe and Simon Burge.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.7 2025/12/21 07:00:27 skrll Exp $");

#include "opt_ddb.h"
#include "opt_kgdb.h"
#include "opt_modular.h"

#include <sys/param.h>
#include <sys/boot_flag.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/kcore.h>
#include <sys/kernel.h>
#include <sys/ksyms.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/reboot.h>
#include <sys/termios.h>

#include <uvm/uvm_extern.h>

#include <dev/cons.h>
#include <dev/ic/comvar.h>
#include <dev/ic/ns16450reg.h>

#include <evbmips/mipssim/mipssimreg.h>
#include <evbmips/mipssim/mipssimvar.h>

#include "ksyms.h"

#if NKSYMS || defined(DDB) || defined(MODULAR)
#include <mips/db_machdep.h>
#include <ddb/db_extern.h>
#endif

#include <mips/cache.h>
#include <mips/locore.h>
#include <mips/cpuregs.h>


#define COMCNRATE       115200          /* not important, emulated device */
#define COM_FREQ        1843200         /* not important, emulated device */

/*
 * QEMU/mipssim sets the CPU frequency to 6 MHz for 64-bit guests and
 * 12 MHz for 32-bit guests.
 */
#ifdef _LP64
#define CPU_FREQ        6       /* MHz */
#else
#define CPU_FREQ        12      /* MHz */
#endif

/* XXX move phys map decl to a general mips location */
/* Maps for VM objects. */
struct vm_map *phys_map = NULL;

struct mipssim_config mipssim_configuration;

/* XXX move mem cluster decls to a general mips location */
int mem_cluster_cnt;
phys_ram_seg_t mem_clusters[VM_PHYSSEG_MAX];

/* XXX move mach_init() prototype to general mips header file */
void            mach_init(u_long, u_long, u_long, u_long);
static void     mach_init_memory(void);

/*
 * Provide a very simple output-only console driver so that we can
 * use printf() before the "real" console is initialised.
 */
static void uart_putc(dev_t, int);
static struct consdev early_console = {
        .cn_putc = uart_putc,
        .cn_dev = makedev(0, 0),
        .cn_pri = CN_DEAD
};

static void
uart_putc(dev_t dev, int c)
{
        volatile uint8_t *data = (void *)MIPS_PHYS_TO_KSEG1(
            MIPSSIM_ISA_IO_BASE + MIPSSIM_UART0_ADDR + com_data);

        *data = (uint8_t)c;
        /* emulated UART, don't need to wait for output to drain */
}

static void
cal_timer(void)
{
        uint32_t cntfreq;

        cntfreq = curcpu()->ci_cpu_freq = CPU_FREQ * 1000 * 1000;

        if (mips_options.mips_cpu_flags & CPU_MIPS_DOUBLE_COUNT)
                cntfreq /= 2;

        curcpu()->ci_cctr_freq = cntfreq;
        curcpu()->ci_cycles_per_hz = (cntfreq + hz / 2) / hz;

        /* Compute number of cycles per 1us (1/MHz). 0.5MHz is for roundup. */
        curcpu()->ci_divisor_delay = ((cntfreq + 500000) / 1000000);
}

/*
 *
 */
void
mach_init(u_long arg0, u_long arg1, u_long arg2, u_long arg3)
{
        struct mipssim_config *mcp = &mipssim_configuration;
        void *kernend;
        extern char edata[], end[];     /* XXX */

        kernend = (void *)mips_round_page(end);

        /* Zero BSS.  QEMU appears to leave some memory uninitialised. */
        memset(edata, 0, end - edata);

        /* enough of a console for printf() to work */
        cn_tab = &early_console;

        /* set CPU model info for sysctl_hw */
        cpu_setmodel("MIPSSIM");

        mips_vector_init(NULL, false);

        /* must be after CPU is identified in mips_vector_init() */
        cal_timer();

        uvm_md_init();

        /*
         * Initialize bus space tags and bring up the main console.
         */
        mipssim_bus_io_init(&mcp->mc_iot, mcp);
        mipssim_dma_init(mcp);

        if (comcnattach(&mcp->mc_iot, MIPSSIM_UART0_ADDR, COMCNRATE,
            COM_FREQ, COM_TYPE_NORMAL,
            (TTYDEF_CFLAG & ~(CSIZE | PARENB)) | CS8) != 0)
                panic("unable to initialize serial console");

        /*
         * No way of passing arguments in mipssim.
         */
        boothowto = RB_AUTOBOOT;
#ifdef KADB
        boothowto |= RB_KDB;
#endif

        mach_init_memory();

        /*
         * Load the available pages into the VM system.
         */
        mips_page_physload(MIPS_KSEG0_START, (vaddr_t)kernend,
            mem_clusters, mem_cluster_cnt, NULL, 0);

        /*
         * Initialize message buffer (at end of core).
         */
        mips_init_msgbuf();

        /*
         * Initialize the virtual memory system.
         */
        pmap_bootstrap();

        /*
         * Allocate uarea page for lwp0 and set it.
         */
        mips_init_lwp0_uarea();

        /*
         * Initialize debuggers, and break into them, if appropriate.
         */
#ifdef DDB
        if (boothowto & RB_KDB)
                Debugger();
#endif
}

/*
 * qemu for mipssim doesn't have a way of passing in the memory size, so
 * we probe.  lwp0 hasn't been set up this early, so use a dummy pcb to
 * allow badaddr() to function.  Limit total RAM to just before the IO
 * memory at MIPSSIM_ISA_IO_BASE.
 */
static void
mach_init_memory(void)
{
        struct lwp *l = curlwp;
        struct pcb dummypcb;
        psize_t memsize;
        size_t addr;
        uint32_t *memptr;
        extern char end[];      /* XXX */
#ifdef MIPS64
        size_t highaddr;
#endif

        l->l_addr = &dummypcb;
        memsize = roundup2(MIPS_KSEG0_TO_PHYS((uintptr_t)(end)), 1024 * 1024);

        for (addr = memsize; addr < MIPSSIM_ISA_IO_BASE; addr += 1024 * 1024) {
#ifdef MEM_DEBUG
                printf("test %zd MB\n", addr / 1024 * 1024);
#endif
                memptr = (void *)MIPS_PHYS_TO_KSEG1(addr - sizeof(*memptr));

                if (badaddr(memptr, sizeof(uint32_t)) < 0)
                        break;

                memsize = addr;
        }
        l->l_addr = NULL;

        physmem = btoc(memsize);

        mem_clusters[0].start = PAGE_SIZE;
        mem_clusters[0].size = memsize - PAGE_SIZE;
        mem_cluster_cnt = 1;

#ifdef _LP64
        /* probe for more memory above ISA I/O "hole" */
        l->l_addr = &dummypcb;

        for (highaddr = addr = MIPSSIM_MORE_MEM_BASE;
            addr < MIPSSIM_MORE_MEM_END;
            addr += 1024 * 1024) {
                memptr = (void *)MIPS_PHYS_TO_XKPHYS(CCA_CACHEABLE,
                                                addr - sizeof(*memptr));
                if (badaddr(memptr, sizeof(uint32_t)) < 0)
                        break;

                highaddr = addr;
#ifdef MEM_DEBUG
                printf("probed %zd MB\n", (addr - MIPSSIM_MORE_MEM_BASE)
                                        / 1024 * 1024);
#endif
        }
        l->l_addr = NULL;

        if (highaddr != MIPSSIM_MORE_MEM_BASE) {
                mem_clusters[1].start = MIPSSIM_MORE_MEM_BASE;
                mem_clusters[1].size = highaddr - MIPSSIM_MORE_MEM_BASE;
                mem_cluster_cnt++;
                physmem += btoc(mem_clusters[1].size);
                memsize += mem_clusters[1].size;
        }
#endif /* _LP64 */

        printf("Memory size: 0x%" PRIxPSIZE " (%" PRIdPSIZE " MB)\n",
            memsize, memsize / 1024 / 1024);
}

void
consinit(void)
{
        /*
         * Everything related to console initialization is done
         * in mach_init().
         */
}

void
cpu_startup(void)
{

        /*
         * Do the common startup items.
         */
        cpu_startup_common();
}

/* XXX try to make this evbmips generic */
void
cpu_reboot(int howto, char *bootstr)
{
        static int waittime = -1;

        /* Take a snapshot before clobbering any registers. */
        savectx(curpcb);

        /* If "always halt" was specified as a boot flag, obey. */
        if (boothowto & RB_HALT)
                howto |= RB_HALT;

        boothowto = howto;

        /* If system is cold, just halt. */
        if (cold) {
                boothowto |= RB_HALT;
                goto haltsys;
        }

        if ((boothowto & RB_NOSYNC) == 0 && waittime < 0) {
                waittime = 0;

                /*
                 * Synchronize the disks....
                 */
                vfs_shutdown();
        }

        /* Disable interrupts. */
        splhigh();

        if (boothowto & RB_DUMP)
                dumpsys();

haltsys:
        /* Run any shutdown hooks. */
        doshutdownhooks();

        /*
         * Firmware may autoboot (depending on settings), and we cannot pass
         * flags to it (at least I haven't figured out how to yet), so
         * we "pseudo-halt" now.
         */
        if (boothowto & RB_HALT) {
                printf("\n");
                printf("The operating system has halted.\n");
                printf("Please press any key to reboot.\n\n");
                cnpollc(true);  /* For proper keyboard command handling */
                cngetc();
                cnpollc(false);
        }

        printf("resetting...\n\n");
        __asm volatile("jr      %0" :: "r"(MIPS_RESET_EXC_VEC));
        printf("Oops, back from reset\n\nSpinning...");
        for (;;)
                /* spin forever */ ;    /* XXX */
        /*NOTREACHED*/
}