// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Early boot support code for BootX bootloader
 *
 *  Copyright (C) 2005 Ben. Herrenschmidt (benh@kernel.crashing.org)
 */

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/of_fdt.h>
#include <generated/utsrelease.h>
#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/page.h>
#include <asm/bootx.h>
#include <asm/btext.h>
#include <asm/io.h>
#include <asm/setup.h>

#undef DEBUG
#define SET_BOOT_BAT

#ifdef DEBUG
#define DBG(fmt...) do { bootx_printf(fmt); } while(0)
#else
#define DBG(fmt...) do { } while(0)
#endif

extern void __start(unsigned long r3, unsigned long r4, unsigned long r5);

static unsigned long __initdata bootx_dt_strbase;
static unsigned long __initdata bootx_dt_strend;
static unsigned long __initdata bootx_node_chosen;
static boot_infos_t * __initdata bootx_info;
static char __initdata bootx_disp_path[256];

/* Is boot-info compatible ? */
#define BOOT_INFO_IS_COMPATIBLE(bi) \
        ((bi)->compatible_version <= BOOT_INFO_VERSION)
#define BOOT_INFO_IS_V2_COMPATIBLE(bi)  ((bi)->version >= 2)
#define BOOT_INFO_IS_V4_COMPATIBLE(bi)  ((bi)->version >= 4)

#ifdef CONFIG_BOOTX_TEXT
static void __init bootx_printf(const char *format, ...)
{
        const char *p, *q, *s;
        va_list args;
        unsigned long v;

        va_start(args, format);
        for (p = format; *p != 0; p = q) {
                for (q = p; *q != 0 && *q != '\n' && *q != '%'; ++q)
                        ;
                if (q > p)
                        btext_drawtext(p, q - p);
                if (*q == 0)
                        break;
                if (*q == '\n') {
                        ++q;
                        btext_flushline();
                        btext_drawstring("\r\n");
                        btext_flushline();
                        continue;
                }
                ++q;
                if (*q == 0)
                        break;
                switch (*q) {
                case 's':
                        ++q;
                        s = va_arg(args, const char *);
                        if (s == NULL)
                                s = "<NULL>";
                        btext_drawstring(s);
                        break;
                case 'x':
                        ++q;
                        v = va_arg(args, unsigned long);
                        btext_drawhex(v);
                        break;
                }
        }
        va_end(args);
}
#else /* CONFIG_BOOTX_TEXT */
static void __init bootx_printf(const char *format, ...) {}
#endif /* CONFIG_BOOTX_TEXT */

static void * __init bootx_early_getprop(unsigned long base,
                                         unsigned long node,
                                         char *prop)
{
        struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
        u32 *ppp = &np->properties;

        while(*ppp) {
                struct bootx_dt_prop *pp =
                        (struct bootx_dt_prop *)(base + *ppp);

                if (strcmp((char *)((unsigned long)pp->name + base),
                           prop) == 0) {
                        return (void *)((unsigned long)pp->value + base);
                }
                ppp = &pp->next;
        }
        return NULL;
}

#define dt_push_token(token, mem) \
        do { \
                *(mem) = ALIGN(*(mem),4); \
                *((u32 *)*(mem)) = token; \
                *(mem) += 4; \
        } while(0)

static unsigned long __init bootx_dt_find_string(char *str)
{
        char *s, *os;

        s = os = (char *)bootx_dt_strbase;
        s += 4;
        while (s <  (char *)bootx_dt_strend) {
                if (strcmp(s, str) == 0)
                        return s - os;
                s += strlen(s) + 1;
        }
        return 0;
}

static void __init bootx_dt_add_prop(char *name, void *data, int size,
                                  unsigned long *mem_end)
{
        unsigned long soff = bootx_dt_find_string(name);
        if (data == NULL)
                size = 0;
        if (soff == 0) {
                bootx_printf("WARNING: Can't find string index for <%s>\n",
                             name);
                return;
        }
        if (size > 0x20000) {
                bootx_printf("WARNING: ignoring large property ");
                bootx_printf("%s length 0x%x\n", name, size);
                return;
        }
        dt_push_token(OF_DT_PROP, mem_end);
        dt_push_token(size, mem_end);
        dt_push_token(soff, mem_end);

        /* push property content */
        if (size && data) {
                memcpy((void *)*mem_end, data, size);
                *mem_end = ALIGN(*mem_end + size, 4);
        }
}

static void __init bootx_add_chosen_props(unsigned long base,
                                          unsigned long *mem_end)
{
        u32 val;

        bootx_dt_add_prop("linux,bootx", NULL, 0, mem_end);

        if (bootx_info->kernelParamsOffset) {
                char *args = (char *)((unsigned long)bootx_info) +
                        bootx_info->kernelParamsOffset;
                bootx_dt_add_prop("bootargs", args, strlen(args) + 1, mem_end);
        }
        if (bootx_info->ramDisk) {
                val = ((unsigned long)bootx_info) + bootx_info->ramDisk;
                bootx_dt_add_prop("linux,initrd-start", &val, 4, mem_end);
                val += bootx_info->ramDiskSize;
                bootx_dt_add_prop("linux,initrd-end", &val, 4, mem_end);
        }
        if (strlen(bootx_disp_path))
                bootx_dt_add_prop("linux,stdout-path", bootx_disp_path,
                                  strlen(bootx_disp_path) + 1, mem_end);
}

static void __init bootx_add_display_props(unsigned long base,
                                           unsigned long *mem_end,
                                           int has_real_node)
{
        boot_infos_t *bi = bootx_info;
        u32 tmp;

        if (has_real_node) {
                bootx_dt_add_prop("linux,boot-display", NULL, 0, mem_end);
                bootx_dt_add_prop("linux,opened", NULL, 0, mem_end);
        } else
                bootx_dt_add_prop("linux,bootx-noscreen", NULL, 0, mem_end);

        tmp = bi->dispDeviceDepth;
        bootx_dt_add_prop("linux,bootx-depth", &tmp, 4, mem_end);
        tmp = bi->dispDeviceRect[2] - bi->dispDeviceRect[0];
        bootx_dt_add_prop("linux,bootx-width", &tmp, 4, mem_end);
        tmp = bi->dispDeviceRect[3] - bi->dispDeviceRect[1];
        bootx_dt_add_prop("linux,bootx-height", &tmp, 4, mem_end);
        tmp = bi->dispDeviceRowBytes;
        bootx_dt_add_prop("linux,bootx-linebytes", &tmp, 4, mem_end);
        tmp = (u32)bi->dispDeviceBase;
        if (tmp == 0)
                tmp = (u32)bi->logicalDisplayBase;
        tmp += bi->dispDeviceRect[1] * bi->dispDeviceRowBytes;
        tmp += bi->dispDeviceRect[0] * ((bi->dispDeviceDepth + 7) / 8);
        bootx_dt_add_prop("linux,bootx-addr", &tmp, 4, mem_end);
}

static void __init bootx_dt_add_string(char *s, unsigned long *mem_end)
{
        unsigned int l = strlen(s) + 1;
        memcpy((void *)*mem_end, s, l);
        bootx_dt_strend = *mem_end = *mem_end + l;
}

static void __init bootx_scan_dt_build_strings(unsigned long base,
                                               unsigned long node,
                                               unsigned long *mem_end)
{
        struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
        u32 *cpp, *ppp = &np->properties;
        unsigned long soff;
        char *namep;

        /* Keep refs to known nodes */
        namep = np->full_name ? (char *)(base + np->full_name) : NULL;
        if (namep == NULL) {
                bootx_printf("Node without a full name !\n");
                namep = "";
        }
        DBG("* strings: %s\n", namep);

        if (!strcmp(namep, "/chosen")) {
                DBG(" detected /chosen ! adding properties names !\n");
                bootx_dt_add_string("linux,bootx", mem_end);
                bootx_dt_add_string("linux,stdout-path", mem_end);
                bootx_dt_add_string("linux,initrd-start", mem_end);
                bootx_dt_add_string("linux,initrd-end", mem_end);
                bootx_dt_add_string("bootargs", mem_end);
                bootx_node_chosen = node;
        }
        if (node == bootx_info->dispDeviceRegEntryOffset) {
                DBG(" detected display ! adding properties names !\n");
                bootx_dt_add_string("linux,boot-display", mem_end);
                bootx_dt_add_string("linux,opened", mem_end);
                strscpy(bootx_disp_path, namep, sizeof(bootx_disp_path));
        }

        /* get and store all property names */
        while (*ppp) {
                struct bootx_dt_prop *pp =
                        (struct bootx_dt_prop *)(base + *ppp);

                namep = pp->name ? (char *)(base + pp->name) : NULL;
                if (namep == NULL || strcmp(namep, "name") == 0)
                        goto next;
                /* get/create string entry */
                soff = bootx_dt_find_string(namep);
                if (soff == 0)
                        bootx_dt_add_string(namep, mem_end);
        next:
                ppp = &pp->next;
        }

        /* do all our children */
        cpp = &np->child;
        while(*cpp) {
                np = (struct bootx_dt_node *)(base + *cpp);
                bootx_scan_dt_build_strings(base, *cpp, mem_end);
                cpp = &np->sibling;
        }
}

static void __init bootx_scan_dt_build_struct(unsigned long base,
                                              unsigned long node,
                                              unsigned long *mem_end)
{
        struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
        u32 *cpp, *ppp = &np->properties;
        char *namep, *p, *ep, *lp;
        int l;

        dt_push_token(OF_DT_BEGIN_NODE, mem_end);

        /* get the node's full name */
        namep = np->full_name ? (char *)(base + np->full_name) : NULL;
        if (namep == NULL)
                namep = "";
        l = strlen(namep);

        DBG("* struct: %s\n", namep);

        /* Fixup an Apple bug where they have bogus \0 chars in the
         * middle of the path in some properties, and extract
         * the unit name (everything after the last '/').
         */
        memcpy((void *)*mem_end, namep, l + 1);
        namep = (char *)*mem_end;
        for (lp = p = namep, ep = namep + l; p < ep; p++) {
                if (*p == '/')
                        lp = namep;
                else if (*p != 0)
                        *lp++ = *p;
        }
        *lp = 0;
        *mem_end = ALIGN((unsigned long)lp + 1, 4);

        /* get and store all properties */
        while (*ppp) {
                struct bootx_dt_prop *pp =
                        (struct bootx_dt_prop *)(base + *ppp);

                namep = pp->name ? (char *)(base + pp->name) : NULL;
                /* Skip "name" */
                if (namep == NULL || !strcmp(namep, "name"))
                        goto next;
                /* Skip "bootargs" in /chosen too as we replace it */
                if (node == bootx_node_chosen && !strcmp(namep, "bootargs"))
                        goto next;

                /* push property head */
                bootx_dt_add_prop(namep,
                                  pp->value ? (void *)(base + pp->value): NULL,
                                  pp->length, mem_end);
        next:
                ppp = &pp->next;
        }

        if (node == bootx_node_chosen) {
                bootx_add_chosen_props(base, mem_end);
                if (bootx_info->dispDeviceRegEntryOffset == 0)
                        bootx_add_display_props(base, mem_end, 0);
        }
        else if (node == bootx_info->dispDeviceRegEntryOffset)
                bootx_add_display_props(base, mem_end, 1);

        /* do all our children */
        cpp = &np->child;
        while(*cpp) {
                np = (struct bootx_dt_node *)(base + *cpp);
                bootx_scan_dt_build_struct(base, *cpp, mem_end);
                cpp = &np->sibling;
        }

        dt_push_token(OF_DT_END_NODE, mem_end);
}

static unsigned long __init bootx_flatten_dt(unsigned long start)
{
        boot_infos_t *bi = bootx_info;
        unsigned long mem_start, mem_end;
        struct boot_param_header *hdr;
        unsigned long base;
        u64 *rsvmap;

        /* Start using memory after the big blob passed by BootX, get
         * some space for the header
         */
        mem_start = mem_end = ALIGN(((unsigned long)bi) + start, 4);
        DBG("Boot params header at: %x\n", mem_start);
        hdr = (struct boot_param_header *)mem_start;
        mem_end += sizeof(struct boot_param_header);
        rsvmap = (u64 *)(ALIGN(mem_end, 8));
        hdr->off_mem_rsvmap = ((unsigned long)rsvmap) - mem_start;
        mem_end = ((unsigned long)rsvmap) + 8 * sizeof(u64);

        /* Get base of tree */
        base = ((unsigned long)bi) + bi->deviceTreeOffset;

        /* Build string array */
        DBG("Building string array at: %x\n", mem_end);
        DBG("Device Tree Base=%x\n", base);
        bootx_dt_strbase = mem_end;
        mem_end += 4;
        bootx_dt_strend = mem_end;
        bootx_scan_dt_build_strings(base, 4, &mem_end);
        /* Add some strings */
        bootx_dt_add_string("linux,bootx-noscreen", &mem_end);
        bootx_dt_add_string("linux,bootx-depth", &mem_end);
        bootx_dt_add_string("linux,bootx-width", &mem_end);
        bootx_dt_add_string("linux,bootx-height", &mem_end);
        bootx_dt_add_string("linux,bootx-linebytes", &mem_end);
        bootx_dt_add_string("linux,bootx-addr", &mem_end);
        /* Wrap up strings */
        hdr->off_dt_strings = bootx_dt_strbase - mem_start;
        hdr->dt_strings_size = bootx_dt_strend - bootx_dt_strbase;

        /* Build structure */
        mem_end = ALIGN(mem_end, 16);
        DBG("Building device tree structure at: %x\n", mem_end);
        hdr->off_dt_struct = mem_end - mem_start;
        bootx_scan_dt_build_struct(base, 4, &mem_end);
        dt_push_token(OF_DT_END, &mem_end);

        /* Finish header */
        hdr->boot_cpuid_phys = 0;
        hdr->magic = OF_DT_HEADER;
        hdr->totalsize = mem_end - mem_start;
        hdr->version = OF_DT_VERSION;
        /* Version 16 is not backward compatible */
        hdr->last_comp_version = 0x10;

        /* Reserve the whole thing and copy the reserve map in, we
         * also bump mem_reserve_cnt to cause further reservations to
         * fail since it's too late.
         */
        mem_end = ALIGN(mem_end, PAGE_SIZE);
        DBG("End of boot params: %x\n", mem_end);
        rsvmap[0] = mem_start;
        rsvmap[1] = mem_end;
        if (bootx_info->ramDisk) {
                rsvmap[2] = ((unsigned long)bootx_info) + bootx_info->ramDisk;
                rsvmap[3] = rsvmap[2] + bootx_info->ramDiskSize;
                rsvmap[4] = 0;
                rsvmap[5] = 0;
        } else {
                rsvmap[2] = 0;
                rsvmap[3] = 0;
        }

        return (unsigned long)hdr;
}


#ifdef CONFIG_BOOTX_TEXT
static void __init btext_welcome(boot_infos_t *bi)
{
        unsigned long flags;
        unsigned long pvr;

        bootx_printf("Welcome to Linux, kernel " UTS_RELEASE "\n");
        bootx_printf("\nlinked at        : 0x%x", KERNELBASE);
        bootx_printf("\nframe buffer at  : 0x%x", bi->dispDeviceBase);
        bootx_printf(" (phys), 0x%x", bi->logicalDisplayBase);
        bootx_printf(" (log)");
        bootx_printf("\nklimit           : 0x%x",(unsigned long)_end);
        bootx_printf("\nboot_info at     : 0x%x", bi);
        __asm__ __volatile__ ("mfmsr %0" : "=r" (flags));
        bootx_printf("\nMSR              : 0x%x", flags);
        __asm__ __volatile__ ("mfspr %0, 287" : "=r" (pvr));
        bootx_printf("\nPVR              : 0x%x", pvr);
        pvr >>= 16;
        if (pvr > 1) {
            __asm__ __volatile__ ("mfspr %0, 1008" : "=r" (flags));
            bootx_printf("\nHID0             : 0x%x", flags);
        }
        if (pvr == 8 || pvr == 12 || pvr == 0x800c) {
            __asm__ __volatile__ ("mfspr %0, 1019" : "=r" (flags));
            bootx_printf("\nICTC             : 0x%x", flags);
        }
#ifdef DEBUG
        bootx_printf("\n\n");
        bootx_printf("bi->deviceTreeOffset   : 0x%x\n",
                     bi->deviceTreeOffset);
        bootx_printf("bi->deviceTreeSize     : 0x%x\n",
                     bi->deviceTreeSize);
#endif
        bootx_printf("\n\n");
}
#endif /* CONFIG_BOOTX_TEXT */

void __init bootx_init(unsigned long r3, unsigned long r4)
{
        boot_infos_t *bi = (boot_infos_t *) r4;
        unsigned long hdr;
        unsigned long space;
        unsigned long ptr;
        char *model;
        unsigned long offset = reloc_offset();

        reloc_got2(offset);

        bootx_info = bi;

        /* We haven't cleared any bss at this point, make sure
         * what we need is initialized
         */
        bootx_dt_strbase = bootx_dt_strend = 0;
        bootx_node_chosen = 0;
        bootx_disp_path[0] = 0;

        if (!BOOT_INFO_IS_V2_COMPATIBLE(bi))
                bi->logicalDisplayBase = bi->dispDeviceBase;

        /* Fixup depth 16 -> 15 as that's what MacOS calls 16bpp */
        if (bi->dispDeviceDepth == 16)
                bi->dispDeviceDepth = 15;


#ifdef CONFIG_BOOTX_TEXT
        ptr = (unsigned long)bi->logicalDisplayBase;
        ptr += bi->dispDeviceRect[1] * bi->dispDeviceRowBytes;
        ptr += bi->dispDeviceRect[0] * ((bi->dispDeviceDepth + 7) / 8);
        btext_setup_display(bi->dispDeviceRect[2] - bi->dispDeviceRect[0],
                            bi->dispDeviceRect[3] - bi->dispDeviceRect[1],
                            bi->dispDeviceDepth, bi->dispDeviceRowBytes,
                            (unsigned long)bi->logicalDisplayBase);
        btext_clearscreen();
        btext_flushscreen();
#endif /* CONFIG_BOOTX_TEXT */

        /*
         * Test if boot-info is compatible.  Done only in config
         * CONFIG_BOOTX_TEXT since there is nothing much we can do
         * with an incompatible version, except display a message
         * and eventually hang the processor...
         *
         * I'll try to keep enough of boot-info compatible in the
         * future to always allow display of this message;
         */
        if (!BOOT_INFO_IS_COMPATIBLE(bi)) {
                bootx_printf(" !!! WARNING - Incompatible version"
                             " of BootX !!!\n\n\n");
                for (;;)
                        ;
        }
        if (bi->architecture != BOOT_ARCH_PCI) {
                bootx_printf(" !!! WARNING - Unsupported machine"
                             " architecture !\n");
                for (;;)
                        ;
        }

#ifdef CONFIG_BOOTX_TEXT
        btext_welcome(bi);
#endif

        /* New BootX enters kernel with MMU off, i/os are not allowed
         * here. This hack will have been done by the boostrap anyway.
         */
        if (bi->version < 4) {
                /*
                 * XXX If this is an iMac, turn off the USB controller.
                 */
                model = (char *) bootx_early_getprop(r4 + bi->deviceTreeOffset,
                                                     4, "model");
                if (model
                    && (strcmp(model, "iMac,1") == 0
                        || strcmp(model, "PowerMac1,1") == 0)) {
                        bootx_printf("iMac,1 detected, shutting down USB\n");
                        out_le32((unsigned __iomem *)0x80880008, 1);    /* XXX */
                }
        }

        /* Get a pointer that points above the device tree, args, ramdisk,
         * etc... to use for generating the flattened tree
         */
        if (bi->version < 5) {
                space = bi->deviceTreeOffset + bi->deviceTreeSize;
                if (bi->ramDisk >= space)
                        space = bi->ramDisk + bi->ramDiskSize;
        } else
                space = bi->totalParamsSize;

        bootx_printf("Total space used by parameters & ramdisk: 0x%x\n", space);

        /* New BootX will have flushed all TLBs and enters kernel with
         * MMU switched OFF, so this should not be useful anymore.
         */
        if (bi->version < 4) {
                unsigned long x __maybe_unused;

                bootx_printf("Touching pages...\n");

                /*
                 * Touch each page to make sure the PTEs for them
                 * are in the hash table - the aim is to try to avoid
                 * getting DSI exceptions while copying the kernel image.
                 */
                for (ptr = ((unsigned long) &_stext) & PAGE_MASK;
                     ptr < (unsigned long)bi + space; ptr += PAGE_SIZE)
                        x = *(volatile unsigned long *)ptr;
        }

        /* Ok, now we need to generate a flattened device-tree to pass
         * to the kernel
         */
        bootx_printf("Preparing boot params...\n");

        hdr = bootx_flatten_dt(space);

#ifdef CONFIG_BOOTX_TEXT
#ifdef SET_BOOT_BAT
        bootx_printf("Preparing BAT...\n");
        btext_prepare_BAT();
#else
        btext_unmap();
#endif
#endif

        reloc_got2(-offset);

        __start(hdr, KERNELBASE + offset, 0);
}