Archipelago » qemu

/*

 * QEMU PC System Emulator

 *

 * Copyright (c) 2003-2004 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "hw.h"

#include "fw_cfg.h"

#include "multiboot.h"

#include "loader.h"

#include "elf.h"

#include "sysemu.h"

/* Show multiboot debug output */

//#define DEBUG_MULTIBOOT

#ifdef DEBUG_MULTIBOOT

#define mb_debug(a...) fprintf(stderr, ## a)

#else

#define mb_debug(a...)

#endif

#define MULTIBOOT_STRUCT_ADDR 0x9000

#if MULTIBOOT_STRUCT_ADDR > 0xf0000

#error multiboot struct needs to fit in 16 bit real mode

#endif

enum {

    /* Multiboot info */

    MBI_FLAGS       = 0,

    MBI_MEM_LOWER   = 4,

    MBI_MEM_UPPER   = 8,

    MBI_BOOT_DEVICE = 12,

    MBI_CMDLINE     = 16,

    MBI_MODS_COUNT  = 20,

    MBI_MODS_ADDR   = 24,

    MBI_MMAP_ADDR   = 48,

    MBI_SIZE        = 88,

    /* Multiboot modules */

    MB_MOD_START    = 0,

    MB_MOD_END      = 4,

    MB_MOD_CMDLINE  = 8,

    MB_MOD_SIZE     = 16,

    /* Region offsets */

    ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,

    ADDR_MBI      = ADDR_E820_MAP + 0x500,

    /* Multiboot flags */

    MULTIBOOT_FLAGS_MEMORY      = 1 << 0,

    MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,

    MULTIBOOT_FLAGS_CMDLINE     = 1 << 2,

    MULTIBOOT_FLAGS_MODULES     = 1 << 3,

    MULTIBOOT_FLAGS_MMAP        = 1 << 6,

};

typedef struct {

    /* buffer holding kernel, cmdlines and mb_infos */

    void *mb_buf;

    /* address in target */

    target_phys_addr_t mb_buf_phys;

    /* size of mb_buf in bytes */

    unsigned mb_buf_size;

    /* offset of mb-info's in bytes */

    target_phys_addr_t offset_mbinfo;

    /* offset in buffer for cmdlines in bytes */

    target_phys_addr_t offset_cmdlines;

    /* offset of modules in bytes */

    target_phys_addr_t offset_mods;

    /* available slots for mb modules infos */

    int mb_mods_avail;

    /* currently used slots of mb modules */

    int mb_mods_count;

} MultibootState;

static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)

{

    int len = strlen(cmdline) + 1;

    target_phys_addr_t p = s->offset_cmdlines;

    pstrcpy((char *)s->mb_buf + p, len, cmdline);

    s->offset_cmdlines += len;

    return s->mb_buf_phys + p;

}

static void mb_add_mod(MultibootState *s,

                       target_phys_addr_t start, target_phys_addr_t end,

                       target_phys_addr_t cmdline_phys)

{

    char *p;

    assert(s->mb_mods_count < s->mb_mods_avail);

    p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;

    stl_p(p + MB_MOD_START,   start);

    stl_p(p + MB_MOD_END,     end);

    stl_p(p + MB_MOD_CMDLINE, cmdline_phys);

    mb_debug("mod%02d: %08x - %08x\n", s->mb_mods_count, start, end);

    s->mb_mods_count++;

}

int load_multiboot(void *fw_cfg,

                   FILE *f,

                   const char *kernel_filename,

                   const char *initrd_filename,

                   const char *kernel_cmdline,

                   int kernel_file_size,

                   uint8_t *header)

{

    int i, is_multiboot = 0;

    uint32_t flags = 0;

    uint32_t mh_entry_addr;

    uint32_t mh_load_addr;

    uint32_t mb_kernel_size;

    MultibootState mbs;

    uint8_t bootinfo[MBI_SIZE];

    uint8_t *mb_bootinfo_data;

    /* Ok, let's see if it is a multiboot image.

       The header is 12x32bit long, so the latest entry may be 8192 - 48. */

    for (i = 0; i < (8192 - 48); i += 4) {

        if (ldl_p(header+i) == 0x1BADB002) {

            uint32_t checksum = ldl_p(header+i+8);

            flags = ldl_p(header+i+4);

            checksum += flags;

            checksum += (uint32_t)0x1BADB002;

            if (!checksum) {

                is_multiboot = 1;

                break;

            }

        }

    }

    if (!is_multiboot)

        return 0; /* no multiboot */

    mb_debug("qemu: I believe we found a multiboot image!\n");

    memset(bootinfo, 0, sizeof(bootinfo));

    memset(&mbs, 0, sizeof(mbs));

    if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */

        fprintf(stderr, "qemu: multiboot knows VBE. we don't.\n");

    }

    if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */

        uint64_t elf_entry;

        uint64_t elf_low, elf_high;

        int kernel_size;

        fclose(f);

        kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,

                               &elf_low, &elf_high, 0, ELF_MACHINE, 0);

        if (kernel_size < 0) {

            fprintf(stderr, "Error while loading elf kernel\n");

            exit(1);

        }

        mh_load_addr = elf_low;

        mb_kernel_size = elf_high - elf_low;

        mh_entry_addr = elf_entry;

        mbs.mb_buf = qemu_malloc(mb_kernel_size);

        if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {

            fprintf(stderr, "Error while fetching elf kernel from rom\n");

            exit(1);

        }

        mb_debug("qemu: loading multiboot-elf kernel (%#x bytes) with entry %#zx\n",

                  mb_kernel_size, (size_t)mh_entry_addr);

    } else {

        /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */

        uint32_t mh_header_addr = ldl_p(header+i+12);

        mh_load_addr = ldl_p(header+i+16);

        uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);

        mh_entry_addr = ldl_p(header+i+28);

        mb_kernel_size = kernel_file_size - mb_kernel_text_offset;

        /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE.

        uint32_t mh_mode_type = ldl_p(header+i+32);

        uint32_t mh_width = ldl_p(header+i+36);

        uint32_t mh_height = ldl_p(header+i+40);

        uint32_t mh_depth = ldl_p(header+i+44); */

        mb_debug("multiboot: mh_header_addr = %#x\n", mh_header_addr);

        mb_debug("multiboot: mh_load_addr = %#x\n", mh_load_addr);

        mb_debug("multiboot: mh_load_end_addr = %#x\n", ldl_p(header+i+20));

        mb_debug("multiboot: mh_bss_end_addr = %#x\n", ldl_p(header+i+24));

        mb_debug("qemu: loading multiboot kernel (%#x bytes) at %#x\n",

                 mb_kernel_size, mh_load_addr);

        mbs.mb_buf = qemu_malloc(mb_kernel_size);

        fseek(f, mb_kernel_text_offset, SEEK_SET);

        if (fread(mbs.mb_buf, 1, mb_kernel_size, f) != mb_kernel_size) {

            fprintf(stderr, "fread() failed\n");

            exit(1);

        }

        fclose(f);

    }

    mbs.mb_buf_phys = mh_load_addr;

    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);

    mbs.offset_mbinfo = mbs.mb_buf_size;

    /* Calculate space for cmdlines and mb_mods */

    mbs.mb_buf_size += strlen(kernel_filename) + 1;

    mbs.mb_buf_size += strlen(kernel_cmdline) + 1;

    if (initrd_filename) {

        const char *r = initrd_filename;

        mbs.mb_buf_size += strlen(r) + 1;

        mbs.mb_mods_avail = 1;

        while ((r = strchr(r, ','))) {

           mbs.mb_mods_avail++;

           r++;

        }

        mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;

    }

    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);

    /* enlarge mb_buf to hold cmdlines and mb-info structs */

    mbs.mb_buf          = qemu_realloc(mbs.mb_buf, mbs.mb_buf_size);

    mbs.offset_cmdlines = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;

    if (initrd_filename) {

        char *next_initrd;

        mbs.offset_mods = mbs.mb_buf_size;

        do {

            char *next_space;

            uint32_t mb_mod_length;

            uint32_t offs = mbs.mb_buf_size;

            next_initrd = strchr(initrd_filename, ',');

            if (next_initrd)

                *next_initrd = '\0';

            /* if a space comes after the module filename, treat everything

               after that as parameters */

            target_phys_addr_t c = mb_add_cmdline(&mbs, initrd_filename);

            if ((next_space = strchr(initrd_filename, ' ')))

                *next_space = '\0';

            mb_debug("multiboot loading module: %s\n", initrd_filename);

            mb_mod_length = get_image_size(initrd_filename);

            if (mb_mod_length < 0) {

                fprintf(stderr, "failed to get %s image size\n", initrd_filename);

                exit(1);

            }

            mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);

            mbs.mb_buf = qemu_realloc(mbs.mb_buf, mbs.mb_buf_size);

            load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);

            mb_add_mod(&mbs, mbs.mb_buf_phys + offs,

                       mbs.mb_buf_phys + offs + mb_mod_length, c);

            mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: %#x\n",

                     (char *)mbs.mb_buf + offs,

                     (char *)mbs.mb_buf + offs + mb_mod_length, c);

            initrd_filename = next_initrd+1;

        } while (next_initrd);

    }

    /* Commandline support */

    char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];

    snprintf(kcmdline, sizeof(kcmdline), "%s %s",

             kernel_filename, kernel_cmdline);

    stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));

    stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);

    stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */

    /* the kernel is where we want it to be now */

    stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY

                                | MULTIBOOT_FLAGS_BOOT_DEVICE

                                | MULTIBOOT_FLAGS_CMDLINE

                                | MULTIBOOT_FLAGS_MODULES

                                | MULTIBOOT_FLAGS_MMAP);

    stl_p(bootinfo + MBI_MEM_LOWER,   640);

    stl_p(bootinfo + MBI_MEM_UPPER,   ram_size / 1024);

    stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8001ffff); /* XXX: use the -boot switch? */

    stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);

    mb_debug("multiboot: mh_entry_addr = %#x\n", mh_entry_addr);

    mb_debug("           mb_buf_phys   = %x\n", mbs.mb_buf_phys);

    mb_debug("           mod_start     = %x\n", mbs.mb_buf_phys + mbs.offset_mods);

    mb_debug("           mb_mods_count = %d\n", mbs.mb_mods_count);

    /* save bootinfo off the stack */

    mb_bootinfo_data = qemu_malloc(sizeof(bootinfo));

    memcpy(mb_bootinfo_data, bootinfo, sizeof(bootinfo));

    /* Pass variables to option rom */

    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);

    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);

    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);

    fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,

                     mbs.mb_buf, mbs.mb_buf_size);

    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);

    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));

    fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,

                     sizeof(bootinfo));

    option_rom[nb_option_roms] = "multiboot.bin";

    nb_option_roms++;

    return 1; /* yes, we are multiboot */

}