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/* ----------------------------------------------------------------------- *
*
* Copyright 2012 Intel Corporation, author: H. Peter Anvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston MA 02110-1301, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* chainbooting - replace the current bootloader completely. This
* is BIOS-specific.
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <dprintf.h>
#include <com32.h>
#include <sys/exec.h>
#include <sys/io.h>
#include "core.h"
#include "menu.h"
#include "fs.h"
#include "config.h"
#include "localboot.h"
#include "bios.h"
#include <syslinux/boot.h>
#include <syslinux/bootrm.h>
#include <syslinux/movebits.h>
#include <syslinux/config.h>
void chainboot_file(const char *file, uint32_t type)
{
uint8_t keeppxe = 0;
const union syslinux_derivative_info *sdi;
struct syslinux_rm_regs regs;
struct syslinux_movelist *fraglist = NULL;
struct syslinux_memmap *mmap = NULL;
struct com32_filedata fd;
com32sys_t reg;
char *stack;
void *buf;
int rv, max, size;
max = 0xA0000; /* Maximum load */
buf = malloc(max);
if (!buf)
goto bail;
rv = open_file(file, &fd);
if (rv == -1)
goto bail;
reg.eax.l = max;
reg.ebx.l = 0;
reg.edx.w[0] = 0;
reg.edi.l = (uint32_t)buf;
reg.ebp.l = -1; /* XXX: limit? */
reg.esi.w[0] = rv;
pm_load_high(®);
size = reg.edi.l - (unsigned long)buf;
if (size > 0xA0000 - 0x7C00) {
printf("Too large for a boostrap (need LINUX instead of KERNEL?)\n");
goto bail;
}
mmap = syslinux_memory_map();
if (!mmap)
goto bail;
sdi = syslinux_derivative_info();
memset(®s, 0, sizeof(regs));
regs.ip = 0x7c00;
if (sdi->c.filesystem == SYSLINUX_FS_SYSLINUX ||
sdi->c.filesystem == SYSLINUX_FS_EXTLINUX) {
if (syslinux_add_movelist(&fraglist, 0x800 - 18,
(addr_t)sdi->r.esbx, 16))
goto bail;
/* DS:SI points to partition info */
regs.esi.l = 0x800 - 18;
}
/*
* For a BSS boot sector we have to transfer the
* superblock.
*/
if (sdi->c.filesystem == SYSLINUX_FS_SYSLINUX &&
type == IMAGE_TYPE_BSS && this_fs->fs_ops->copy_super(buf))
goto bail;
if (sdi->c.filesystem == SYSLINUX_FS_PXELINUX) {
keeppxe = 0x03; /* Chainloading + keep PXE */
stack = (char *)sdi->r.fssi;
/*
* Set up the registers with their initial values
*/
regs.eax.l = *(uint32_t *)&stack[36];
regs.ecx.l = *(uint32_t *)&stack[32];
regs.edx.l = *(uint32_t *)&stack[28];
regs.ebx.l = *(uint32_t *)&stack[24];
regs.esp.l = sdi->rr.r.esi.w[0] + 44;
regs.ebp.l = *(uint32_t *)&stack[16];
regs.esi.l = *(uint32_t *)&stack[12];
regs.edi.l = *(uint32_t *)&stack[8];
regs.es = *(uint16_t *)&stack[4];
regs.ss = sdi->rr.r.fs;
regs.ds = *(uint16_t *)&stack[6];
regs.fs = *(uint16_t *)&stack[2];
regs.gs = *(uint16_t *)&stack[0];
} else {
const uint16_t *esdi = (const uint16_t *)sdi->disk.esdi_ptr;
regs.esp.l = (uint16_t)(unsigned long)StackBuf + 44;
/*
* DON'T DO THIS FOR PXELINUX...
* For PXE, ES:BX -> PXENV+, and this would
* corrupt that use.
*
* Restore ES:DI -> $PnP (if we were ourselves
* called that way...)
*/
regs.edi.w[0] = esdi[0]; /* New DI */
regs.es = esdi[2]; /* New ES */
regs.edx.l = sdi->rr.r.edx.b[0]; /* Drive number -> DL */
}
if (syslinux_add_movelist(&fraglist, 0x7c00, (addr_t)buf, size))
goto bail;
syslinux_shuffle_boot_rm(fraglist, mmap, keeppxe, ®s);
bail:
if (fraglist)
syslinux_free_movelist(fraglist);
if (mmap)
syslinux_free_memmap(mmap);
if (buf)
free(buf);
return;
}
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