Split bootsector execution code out into bootsector.c.
Added basic El Torito ISO image boot capability
This commit is contained in:
parent
bde8878eef
commit
2cf1e33df1
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@ -0,0 +1,111 @@
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/*
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* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/**
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* @file
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*
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* x86 bootsector image format
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*
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*/
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#include <errno.h>
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#include <realmode.h>
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#include <biosint.h>
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#include <bootsector.h>
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/** Vector for storing original INT 18 handler
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*
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* We do not chain to this vector, so there is no need to place it in
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* .text16.
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*/
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static struct segoff int18_vector;
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/** Vector for storing original INT 19 handler
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*
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* We do not chain to this vector, so there is no need to place it in
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* .text16.
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*/
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static struct segoff int19_vector;
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/** Restart point for INT 18 or 19 */
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extern void bootsector_exec_fail ( void );
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/**
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* Jump to preloaded bootsector
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*
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* @v segment Real-mode segment
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* @v offset Real-mode offset
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* @v drive Drive number to pass to boot sector
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* @ret rc Return status code
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*/
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int call_bootsector ( unsigned int segment, unsigned int offset,
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unsigned int drive ) {
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int discard_b, discard_D, discard_d;
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DBG ( "Booting from boot sector at %04x:%04x\n", segment, offset );
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/* Hook INTs 18 and 19 to capture failure paths */
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hook_bios_interrupt ( 0x18, ( unsigned int ) bootsector_exec_fail,
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&int18_vector );
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hook_bios_interrupt ( 0x19, ( unsigned int ) bootsector_exec_fail,
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&int19_vector );
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/* Boot the loaded sector
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*
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* We assume that the boot sector may completely destroy our
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* real-mode stack, so we preserve everything we need in
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* static storage.
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*/
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__asm__ __volatile__ ( REAL_CODE ( /* Save return address off-stack */
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"popw %%cs:saved_retaddr\n\t"
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/* Save stack pointer */
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"movw %%ss, %%ax\n\t"
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"movw %%ax, %%cs:saved_ss\n\t"
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"movw %%sp, %%cs:saved_sp\n\t"
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/* Jump to boot sector */
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"pushw %%bx\n\t"
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"pushw %%di\n\t"
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"lret\n\t"
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/* Preserved variables */
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"\nsaved_ss: .word 0\n\t"
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"\nsaved_sp: .word 0\n\t"
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"\nsaved_retaddr: .word 0\n\t"
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/* Boot failure return point */
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"\nbootsector_exec_fail:\n\t"
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/* Restore stack pointer */
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"movw %%cs:saved_ss, %%ax\n\t"
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"movw %%ax, %%ss\n\t"
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"movw %%cs:saved_sp, %%sp\n\t"
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/* Return via saved address */
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"jmp *%%cs:saved_retaddr\n\t" )
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: "=b" ( discard_b ), "=D" ( discard_D ),
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"=d" ( discard_d )
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: "b" ( segment ), "D" ( offset ),
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"d" ( drive )
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: "eax", "ecx", "esi", "ebp" );
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DBG ( "Booted disk returned via INT 18 or 19\n" );
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/* Unhook INTs 18 and 19 */
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unhook_bios_interrupt ( 0x18, ( unsigned int ) bootsector_exec_fail,
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&int18_vector );
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unhook_bios_interrupt ( 0x19, ( unsigned int ) bootsector_exec_fail,
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&int19_vector );
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return -ECANCELED;
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}
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@ -0,0 +1,334 @@
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/*
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* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/**
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* @file
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*
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* El Torito bootable ISO image format
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*
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*/
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#include <stdint.h>
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#include <errno.h>
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#include <assert.h>
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#include <realmode.h>
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#include <bootsector.h>
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#include <int13.h>
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#include <gpxe/uaccess.h>
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#include <gpxe/image.h>
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#include <gpxe/segment.h>
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#include <gpxe/ramdisk.h>
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#include <gpxe/shutdown.h>
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#define ISO9660_BLKSIZE 2048
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#define ELTORITO_VOL_DESC_OFFSET ( 17 * ISO9660_BLKSIZE )
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/** An El Torito Boot Record Volume Descriptor */
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struct eltorito_vol_desc {
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/** Boot record indicator; must be 0 */
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uint8_t record_indicator;
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/** ISO-9660 identifier; must be "CD001" */
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uint8_t iso9660_id[5];
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/** Version, must be 1 */
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uint8_t version;
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/** Boot system indicator; must be "EL TORITO SPECIFICATION" */
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uint8_t system_indicator[32];
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/** Unused */
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uint8_t unused[32];
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/** Boot catalog sector */
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uint32_t sector;
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} __attribute__ (( packed ));
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/** An El Torito Boot Catalog Validation Entry */
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struct eltorito_validation_entry {
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/** Header ID; must be 1 */
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uint8_t header_id;
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/** Platform ID
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*
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* 0 = 80x86
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* 1 = PowerPC
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* 2 = Mac
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*/
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uint8_t platform_id;
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/** Reserved */
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uint16_t reserved;
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/** ID string */
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uint8_t id_string[24];
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/** Checksum word */
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uint16_t checksum;
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/** Signature; must be 0xaa55 */
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uint16_t signature;
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} __attribute__ (( packed ));
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/** A bootable entry in the El Torito Boot Catalog */
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struct eltorito_boot_entry {
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/** Boot indicator
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*
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* Must be @c ELTORITO_BOOTABLE for a bootable ISO image
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*/
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uint8_t indicator;
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/** Media type
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*
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*/
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uint8_t media_type;
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/** Load segment */
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uint16_t load_segment;
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/** System type */
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uint8_t filesystem;
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/** Unused */
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uint8_t reserved_a;
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/** Sector count */
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uint16_t length;
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/** Starting sector */
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uint32_t start;
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/** Unused */
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uint8_t reserved_b[20];
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} __attribute__ (( packed ));
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/** Boot indicator for a bootable ISO image */
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#define ELTORITO_BOOTABLE 0x88
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/** El Torito media types */
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enum eltorito_media_type {
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/** No emulation */
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ELTORITO_NO_EMULATION = 0,
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};
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struct image_type eltorito_image_type __image_type ( PROBE_NORMAL );
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/**
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* Calculate 16-bit word checksum
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*
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* @v data Data to checksum
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* @v len Length (in bytes, must be even)
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* @ret sum Checksum
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*/
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static unsigned int word_checksum ( void *data, size_t len ) {
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uint16_t *words;
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uint16_t sum = 0;
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for ( words = data ; len ; words++, len -= 2 ) {
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sum += *words;
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}
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return sum;
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}
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/**
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* Execute El Torito image
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*
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* @v image El Torito image
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* @ret rc Return status code
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*/
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static int eltorito_exec ( struct image *image ) {
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struct ramdisk ramdisk;
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struct int13_drive int13_drive;
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unsigned int load_segment = image->priv.ul;
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unsigned int load_offset = ( load_segment ? 0 : 0x7c00 );
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int rc;
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memset ( &ramdisk, 0, sizeof ( ramdisk ) );
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init_ramdisk ( &ramdisk, image->data, image->len, ISO9660_BLKSIZE );
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memset ( &int13_drive, 0, sizeof ( int13_drive ) );
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int13_drive.blockdev = &ramdisk.blockdev;
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register_int13_drive ( &int13_drive );
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if ( ( rc = call_bootsector ( load_segment, load_offset,
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int13_drive.drive ) ) != 0 ) {
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DBGC ( image, "ElTorito %p boot failed: %s\n",
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image, strerror ( rc ) );
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goto err;
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}
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rc = -ECANCELED; /* -EIMPOSSIBLE */
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err:
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unregister_int13_drive ( &int13_drive );
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return rc;
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}
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/**
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* Read and verify El Torito Boot Record Volume Descriptor
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*
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* @v image El Torito file
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* @ret catalog_offset Offset of Boot Catalog
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* @ret rc Return status code
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*/
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static int eltorito_read_voldesc ( struct image *image,
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unsigned long *catalog_offset ) {
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static const struct eltorito_vol_desc vol_desc_signature = {
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.record_indicator = 0,
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.iso9660_id = "CD001",
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.version = 1,
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.system_indicator = "EL TORITO SPECIFICATION",
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};
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struct eltorito_vol_desc vol_desc;
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/* Sanity check */
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if ( image->len < ( ELTORITO_VOL_DESC_OFFSET + ISO9660_BLKSIZE ) ) {
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DBGC ( image, "ElTorito %p too short\n", image );
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return -ENOEXEC;
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}
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/* Read and verify Boot Record Volume Descriptor */
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copy_from_user ( &vol_desc, image->data, ELTORITO_VOL_DESC_OFFSET,
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sizeof ( vol_desc ) );
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if ( memcmp ( &vol_desc, &vol_desc_signature,
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offsetof ( typeof ( vol_desc ), sector ) ) != 0 ) {
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DBGC ( image, "ElTorito %p invalid Boot Record Volume "
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"Descriptor\n", image );
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return -ENOEXEC;
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}
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*catalog_offset = ( vol_desc.sector * ISO9660_BLKSIZE );
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DBGC ( image, "ElTorito %p boot catalog at offset %#lx\n",
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image, *catalog_offset );
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return 0;
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}
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/**
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* Read and verify El Torito Boot Catalog
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*
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* @v image El Torito file
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* @v catalog_offset Offset of Boot Catalog
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* @ret boot_entry El Torito boot entry
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* @ret rc Return status code
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*/
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static int eltorito_read_catalog ( struct image *image,
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unsigned long catalog_offset,
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struct eltorito_boot_entry *boot_entry ) {
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struct eltorito_validation_entry validation_entry;
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/* Sanity check */
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if ( image->len < ( catalog_offset + ISO9660_BLKSIZE ) ) {
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DBGC ( image, "ElTorito %p bad boot catalog offset %#lx\n",
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image, catalog_offset );
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return -ENOEXEC;
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}
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/* Read and verify the Validation Entry of the Boot Catalog */
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copy_from_user ( &validation_entry, image->data, catalog_offset,
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sizeof ( validation_entry ) );
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if ( word_checksum ( &validation_entry,
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sizeof ( validation_entry ) ) != 0 ) {
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DBGC ( image, "ElTorito %p bad Validation Entry checksum\n",
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image );
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return -ENOEXEC;
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}
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/* Read and verify the Initial/Default entry */
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copy_from_user ( boot_entry, image->data,
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( catalog_offset + sizeof ( validation_entry ) ),
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sizeof ( *boot_entry ) );
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if ( boot_entry->indicator != ELTORITO_BOOTABLE ) {
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DBGC ( image, "ElTorito %p not bootable\n", image );
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return -ENOEXEC;
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}
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if ( boot_entry->media_type != ELTORITO_NO_EMULATION ) {
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DBGC ( image, "ElTorito %p cannot support media type %d\n",
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image, boot_entry->media_type );
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return -ENOTSUP;
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}
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DBGC ( image, "ElTorito %p media type %d segment %04x\n",
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image, boot_entry->media_type, boot_entry->load_segment );
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return 0;
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}
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/**
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* Load El Torito virtual disk image into memory
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*
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* @v image El Torito file
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* @v boot_entry El Torito boot entry
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* @ret rc Return status code
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*/
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static int eltorito_load_disk ( struct image *image,
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struct eltorito_boot_entry *boot_entry ) {
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unsigned long start = ( boot_entry->start * ISO9660_BLKSIZE );
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unsigned long length = ( boot_entry->length * ISO9660_BLKSIZE );
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unsigned int load_segment;
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userptr_t buffer;
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int rc;
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/* Sanity check */
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if ( image->len < ( start + length ) ) {
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DBGC ( image, "ElTorito %p virtual disk lies outside image\n",
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image );
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return -ENOEXEC;
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}
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DBGC ( image, "ElTorito %p virtual disk at %#lx+%#lx\n",
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image, start, length );
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/* Calculate load address */
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load_segment = boot_entry->load_segment;
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||||||
|
buffer = real_to_user ( load_segment, ( load_segment ? 0 : 0x7c00 ) );
|
||||||
|
|
||||||
|
/* Verify and prepare segment */
|
||||||
|
if ( ( rc = prep_segment ( buffer, length, length ) ) != 0 ) {
|
||||||
|
DBGC ( image, "ElTorito %p could not prepare segment: %s\n",
|
||||||
|
image, strerror ( rc ) );
|
||||||
|
return rc;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Copy image to segment */
|
||||||
|
memcpy_user ( buffer, 0, image->data, start, length );
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Load El Torito image into memory
|
||||||
|
*
|
||||||
|
* @v image El Torito file
|
||||||
|
* @ret rc Return status code
|
||||||
|
*/
|
||||||
|
int eltorito_load ( struct image *image ) {
|
||||||
|
struct eltorito_boot_entry boot_entry;
|
||||||
|
unsigned long bootcat_offset;
|
||||||
|
int rc;
|
||||||
|
|
||||||
|
/* Read Boot Record Volume Descriptor, if present */
|
||||||
|
if ( ( rc = eltorito_read_voldesc ( image, &bootcat_offset ) ) != 0 )
|
||||||
|
return rc;
|
||||||
|
|
||||||
|
/* This is an El Torito image, valid or otherwise */
|
||||||
|
if ( ! image->type )
|
||||||
|
image->type = &eltorito_image_type;
|
||||||
|
|
||||||
|
/* Read Boot Catalog */
|
||||||
|
if ( ( rc = eltorito_read_catalog ( image, bootcat_offset,
|
||||||
|
&boot_entry ) ) != 0 )
|
||||||
|
return rc;
|
||||||
|
|
||||||
|
/* Load Virtual Disk image */
|
||||||
|
if ( ( rc = eltorito_load_disk ( image, &boot_entry ) ) != 0 )
|
||||||
|
return rc;
|
||||||
|
|
||||||
|
/* Record load segment in image private data field */
|
||||||
|
image->priv.ul = boot_entry.load_segment;
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/** El Torito image type */
|
||||||
|
struct image_type eltorito_image_type __image_type ( PROBE_NORMAL ) = {
|
||||||
|
.name = "El Torito",
|
||||||
|
.load = eltorito_load,
|
||||||
|
.exec = eltorito_exec,
|
||||||
|
};
|
|
@ -0,0 +1,12 @@
|
||||||
|
#ifndef _BOOTSECTOR_H
|
||||||
|
#define _BOOTSECTOR_H
|
||||||
|
|
||||||
|
/** @file
|
||||||
|
*
|
||||||
|
* x86 bootsector image format
|
||||||
|
*/
|
||||||
|
|
||||||
|
extern int call_bootsector ( unsigned int segment, unsigned int offset,
|
||||||
|
unsigned int drive );
|
||||||
|
|
||||||
|
#endif /* _BOOTSECTOR_H */
|
|
@ -37,6 +37,8 @@ struct block_device;
|
||||||
#define INT13_EXTENDED_WRITE 0x43
|
#define INT13_EXTENDED_WRITE 0x43
|
||||||
/** Get extended drive parameters */
|
/** Get extended drive parameters */
|
||||||
#define INT13_GET_EXTENDED_PARAMETERS 0x48
|
#define INT13_GET_EXTENDED_PARAMETERS 0x48
|
||||||
|
/** Get CD-ROM status / terminate emulation */
|
||||||
|
#define INT13_CDROM_STATUS_TERMINATE 0x4b
|
||||||
|
|
||||||
/** @} */
|
/** @} */
|
||||||
|
|
||||||
|
|
|
@ -26,6 +26,7 @@
|
||||||
#include <realmode.h>
|
#include <realmode.h>
|
||||||
#include <bios.h>
|
#include <bios.h>
|
||||||
#include <biosint.h>
|
#include <biosint.h>
|
||||||
|
#include <bootsector.h>
|
||||||
#include <int13.h>
|
#include <int13.h>
|
||||||
|
|
||||||
/** @file
|
/** @file
|
||||||
|
@ -44,23 +45,6 @@ static struct segoff __text16 ( int13_vector );
|
||||||
/** Assembly wrapper */
|
/** Assembly wrapper */
|
||||||
extern void int13_wrapper ( void );
|
extern void int13_wrapper ( void );
|
||||||
|
|
||||||
/** Vector for storing original INT 18 handler
|
|
||||||
*
|
|
||||||
* We do not chain to this vector, so there is no need to place it in
|
|
||||||
* .text16.
|
|
||||||
*/
|
|
||||||
static struct segoff int18_vector;
|
|
||||||
|
|
||||||
/** Vector for storing original INT 19 handler
|
|
||||||
*
|
|
||||||
* We do not chain to this vector, so there is no need to place it in
|
|
||||||
* .text16.
|
|
||||||
*/
|
|
||||||
static struct segoff int19_vector;
|
|
||||||
|
|
||||||
/** Restart point for INT 18 or 19 */
|
|
||||||
extern void int13_exec_fail ( void );
|
|
||||||
|
|
||||||
/** List of registered emulated drives */
|
/** List of registered emulated drives */
|
||||||
static LIST_HEAD ( drives );
|
static LIST_HEAD ( drives );
|
||||||
|
|
||||||
|
@ -114,6 +98,13 @@ static int int13_rw_sectors ( struct int13_drive *drive,
|
||||||
unsigned int count;
|
unsigned int count;
|
||||||
userptr_t buffer;
|
userptr_t buffer;
|
||||||
|
|
||||||
|
/* Validate blocksize */
|
||||||
|
if ( blockdev->blksize != INT13_BLKSIZE ) {
|
||||||
|
DBG ( "Invalid blocksize (%zd) for non-extended read/write\n",
|
||||||
|
blockdev->blksize );
|
||||||
|
return -INT13_STATUS_INVALID;
|
||||||
|
}
|
||||||
|
|
||||||
/* Calculate parameters */
|
/* Calculate parameters */
|
||||||
cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 2 ) | ix86->regs.ch );
|
cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 2 ) | ix86->regs.ch );
|
||||||
assert ( cylinder < drive->cylinders );
|
assert ( cylinder < drive->cylinders );
|
||||||
|
@ -129,13 +120,6 @@ static int int13_rw_sectors ( struct int13_drive *drive,
|
||||||
DBG ( "C/H/S %d/%d/%d = LBA %#lx <-> %04x:%04x (count %d)\n", cylinder,
|
DBG ( "C/H/S %d/%d/%d = LBA %#lx <-> %04x:%04x (count %d)\n", cylinder,
|
||||||
head, sector, lba, ix86->segs.es, ix86->regs.bx, count );
|
head, sector, lba, ix86->segs.es, ix86->regs.bx, count );
|
||||||
|
|
||||||
/* Validate blocksize */
|
|
||||||
if ( blockdev->blksize != INT13_BLKSIZE ) {
|
|
||||||
DBG ( "Invalid blocksize (%zd) for non-extended read/write\n",
|
|
||||||
blockdev->blksize );
|
|
||||||
return -INT13_STATUS_INVALID;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Read from / write to block device */
|
/* Read from / write to block device */
|
||||||
if ( io ( blockdev, lba, count, buffer ) != 0 )
|
if ( io ( blockdev, lba, count, buffer ) != 0 )
|
||||||
return -INT13_STATUS_READ_ERROR;
|
return -INT13_STATUS_READ_ERROR;
|
||||||
|
@ -333,6 +317,38 @@ static int int13_get_extended_parameters ( struct int13_drive *drive,
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
struct int13_cdrom_specification {
|
||||||
|
/** Size of packet in bytes */
|
||||||
|
uint8_t size;
|
||||||
|
/** Boot media type */
|
||||||
|
uint8_t media_type;
|
||||||
|
/** Drive number */
|
||||||
|
uint8_t drive;
|
||||||
|
};
|
||||||
|
|
||||||
|
/**
|
||||||
|
* INT 13, 4b - Get CD-ROM status / terminate emulation
|
||||||
|
*
|
||||||
|
* @v drive Emulated drive
|
||||||
|
* @v ds:si El Torito specification packet to fill in
|
||||||
|
* @ret status Status code
|
||||||
|
*/
|
||||||
|
static int int13_cdrom_status_terminate ( struct int13_drive *drive,
|
||||||
|
struct i386_all_regs *ix86 ) {
|
||||||
|
struct int13_cdrom_specification specification;
|
||||||
|
|
||||||
|
DBG ( "Get CD-ROM emulation parameters to %04x:%04x\n",
|
||||||
|
ix86->segs.ds, ix86->regs.di );
|
||||||
|
|
||||||
|
memset ( &specification, 0, sizeof ( specification ) );
|
||||||
|
specification.size = sizeof ( specification );
|
||||||
|
specification.drive = drive->drive;
|
||||||
|
|
||||||
|
copy_to_real ( ix86->segs.ds, ix86->regs.si, &specification,
|
||||||
|
sizeof ( specification ) );
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* INT 13 handler
|
* INT 13 handler
|
||||||
*
|
*
|
||||||
|
@ -346,7 +362,7 @@ static void int13 ( struct i386_all_regs *ix86 ) {
|
||||||
if ( drive->drive != ix86->regs.dl )
|
if ( drive->drive != ix86->regs.dl )
|
||||||
continue;
|
continue;
|
||||||
|
|
||||||
DBG ( "INT 13,%02x (%02x): ", command, drive->drive );
|
DBG ( "INT 13,%04x (%02x): ", ix86->regs.ax, drive->drive );
|
||||||
|
|
||||||
switch ( command ) {
|
switch ( command ) {
|
||||||
case INT13_RESET:
|
case INT13_RESET:
|
||||||
|
@ -379,6 +395,9 @@ static void int13 ( struct i386_all_regs *ix86 ) {
|
||||||
case INT13_GET_EXTENDED_PARAMETERS:
|
case INT13_GET_EXTENDED_PARAMETERS:
|
||||||
status = int13_get_extended_parameters ( drive, ix86 );
|
status = int13_get_extended_parameters ( drive, ix86 );
|
||||||
break;
|
break;
|
||||||
|
case INT13_CDROM_STATUS_TERMINATE:
|
||||||
|
status = int13_cdrom_status_terminate ( drive, ix86 );
|
||||||
|
break;
|
||||||
default:
|
default:
|
||||||
DBG ( "*** Unrecognised INT 13 ***\n" );
|
DBG ( "*** Unrecognised INT 13 ***\n" );
|
||||||
status = -INT13_STATUS_INVALID;
|
status = -INT13_STATUS_INVALID;
|
||||||
|
@ -398,6 +417,8 @@ static void int13 ( struct i386_all_regs *ix86 ) {
|
||||||
|
|
||||||
/* Set OF to indicate to wrapper not to chain this call */
|
/* Set OF to indicate to wrapper not to chain this call */
|
||||||
ix86->flags |= OF;
|
ix86->flags |= OF;
|
||||||
|
|
||||||
|
break;
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -453,6 +474,10 @@ static void guess_int13_geometry ( struct int13_drive *drive ) {
|
||||||
unsigned long blocks_per_cyl;
|
unsigned long blocks_per_cyl;
|
||||||
unsigned int i;
|
unsigned int i;
|
||||||
|
|
||||||
|
/* Don't even try when the blksize is invalid for C/H/S access */
|
||||||
|
if ( drive->blockdev->blksize != INT13_BLKSIZE )
|
||||||
|
return;
|
||||||
|
|
||||||
/* Scan through partition table and modify guesses for heads
|
/* Scan through partition table and modify guesses for heads
|
||||||
* and sectors_per_track if we find any used partitions.
|
* and sectors_per_track if we find any used partitions.
|
||||||
*/
|
*/
|
||||||
|
@ -564,6 +589,7 @@ void unregister_int13_drive ( struct int13_drive *drive ) {
|
||||||
int int13_boot ( unsigned int drive ) {
|
int int13_boot ( unsigned int drive ) {
|
||||||
int status, signature;
|
int status, signature;
|
||||||
int discard_c, discard_d;
|
int discard_c, discard_d;
|
||||||
|
int rc;
|
||||||
|
|
||||||
DBG ( "Booting from INT 13 drive %02x\n", drive );
|
DBG ( "Booting from INT 13 drive %02x\n", drive );
|
||||||
|
|
||||||
|
@ -593,48 +619,11 @@ int int13_boot ( unsigned int drive ) {
|
||||||
return -ENOEXEC;
|
return -ENOEXEC;
|
||||||
}
|
}
|
||||||
|
|
||||||
/* Hook INTs 18 and 19 to capture failure paths */
|
|
||||||
hook_bios_interrupt ( 0x18, ( unsigned int ) int13_exec_fail,
|
|
||||||
&int18_vector );
|
|
||||||
hook_bios_interrupt ( 0x19, ( unsigned int ) int13_exec_fail,
|
|
||||||
&int19_vector );
|
|
||||||
|
|
||||||
/* Boot the loaded sector
|
|
||||||
*
|
|
||||||
* We assume that the boot sector may completely destroy our
|
|
||||||
* real-mode stack, so we preserve everything we need in
|
|
||||||
* static storage.
|
|
||||||
*/
|
|
||||||
__asm__ __volatile__ ( REAL_CODE ( /* Save return address off-stack */
|
|
||||||
"popw %%cs:int13_saved_retaddr\n\t"
|
|
||||||
/* Save stack pointer */
|
|
||||||
"movw %%ss, %%ax\n\t"
|
|
||||||
"movw %%ax, %%cs:int13_saved_ss\n\t"
|
|
||||||
"movw %%sp, %%cs:int13_saved_sp\n\t"
|
|
||||||
/* Jump to boot sector */
|
/* Jump to boot sector */
|
||||||
"ljmp $0, $0x7c00\n\t"
|
if ( ( rc = call_bootsector ( 0x0, 0x7c00, drive ) ) != 0 ) {
|
||||||
/* Preserved variables */
|
DBG ( "INT 13 drive %02x boot returned\n", drive );
|
||||||
"\nint13_saved_ss: .word 0\n\t"
|
return rc;
|
||||||
"\nint13_saved_sp: .word 0\n\t"
|
}
|
||||||
"\nint13_saved_retaddr: .word 0\n\t"
|
|
||||||
/* Boot failure return point */
|
|
||||||
"\nint13_exec_fail:\n\t"
|
|
||||||
/* Restore stack pointer */
|
|
||||||
"movw %%cs:int13_saved_ss, %%ax\n\t"
|
|
||||||
"movw %%ax, %%ss\n\t"
|
|
||||||
"movw %%cs:int13_saved_sp, %%sp\n\t"
|
|
||||||
/* Return via saved address */
|
|
||||||
"jmp *%%cs:int13_saved_retaddr\n\t")
|
|
||||||
: "=d" ( discard_d ) : "d" ( drive )
|
|
||||||
: "eax", "ebx", "ecx", "esi", "edi", "ebp" );
|
|
||||||
|
|
||||||
DBG ( "Booted disk returned via INT 18 or 19\n" );
|
return -ECANCELED; /* -EIMPOSSIBLE */
|
||||||
|
|
||||||
/* Unhook INTs 18 and 19 */
|
|
||||||
unhook_bios_interrupt ( 0x18, ( unsigned int ) int13_exec_fail,
|
|
||||||
&int18_vector );
|
|
||||||
unhook_bios_interrupt ( 0x19, ( unsigned int ) int13_exec_fail,
|
|
||||||
&int19_vector );
|
|
||||||
|
|
||||||
return -ECANCELED;
|
|
||||||
}
|
}
|
||||||
|
|
|
@ -143,6 +143,9 @@ REQUIRE_OBJECT ( script );
|
||||||
#ifdef IMAGE_BZIMAGE
|
#ifdef IMAGE_BZIMAGE
|
||||||
REQUIRE_OBJECT ( bzimage );
|
REQUIRE_OBJECT ( bzimage );
|
||||||
#endif
|
#endif
|
||||||
|
#ifdef IMAGE_ELTORITO
|
||||||
|
REQUIRE_OBJECT ( eltorito );
|
||||||
|
#endif
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Drag in all requested commands
|
* Drag in all requested commands
|
||||||
|
|
|
@ -0,0 +1,91 @@
|
||||||
|
/*
|
||||||
|
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
|
||||||
|
*
|
||||||
|
* 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; either version 2 of the
|
||||||
|
* License, or any later version.
|
||||||
|
*
|
||||||
|
* This program is distributed in the hope that it will be useful, but
|
||||||
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||||
|
* General Public License for more details.
|
||||||
|
*
|
||||||
|
* You should have received a copy of the GNU General Public License
|
||||||
|
* along with this program; if not, write to the Free Software
|
||||||
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include <gpxe/blockdev.h>
|
||||||
|
#include <gpxe/ramdisk.h>
|
||||||
|
|
||||||
|
/**
|
||||||
|
* @file
|
||||||
|
*
|
||||||
|
* RAM disks
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
|
||||||
|
static inline __attribute__ (( always_inline )) struct ramdisk *
|
||||||
|
block_to_ramdisk ( struct block_device *blockdev ) {
|
||||||
|
return container_of ( blockdev, struct ramdisk, blockdev );
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Read block
|
||||||
|
*
|
||||||
|
* @v blockdev Block device
|
||||||
|
* @v block Block number
|
||||||
|
* @v count Block count
|
||||||
|
* @v buffer Data buffer
|
||||||
|
* @ret rc Return status code
|
||||||
|
*/
|
||||||
|
static int ramdisk_read ( struct block_device *blockdev, uint64_t block,
|
||||||
|
unsigned long count, userptr_t buffer ) {
|
||||||
|
struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
|
||||||
|
unsigned long offset = ( block * blockdev->blksize );
|
||||||
|
unsigned long length = ( count * blockdev->blksize );
|
||||||
|
|
||||||
|
DBGC ( ramdisk, "RAMDISK %p reading [%lx,%lx)\n",
|
||||||
|
ramdisk, offset, length );
|
||||||
|
|
||||||
|
memcpy_user ( buffer, 0, ramdisk->data, offset, length );
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Write block
|
||||||
|
*
|
||||||
|
* @v blockdev Block device
|
||||||
|
* @v block Block number
|
||||||
|
* @v count Block count
|
||||||
|
* @v buffer Data buffer
|
||||||
|
* @ret rc Return status code
|
||||||
|
*/
|
||||||
|
static int ramdisk_write ( struct block_device *blockdev, uint64_t block,
|
||||||
|
unsigned long count, userptr_t buffer ) {
|
||||||
|
struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
|
||||||
|
unsigned long offset = ( block * blockdev->blksize );
|
||||||
|
unsigned long length = ( count * blockdev->blksize );
|
||||||
|
|
||||||
|
DBGC ( ramdisk, "RAMDISK %p writing [%lx,%lx)\n",
|
||||||
|
ramdisk, offset, length );
|
||||||
|
|
||||||
|
memcpy_user ( ramdisk->data, offset, buffer, 0, length );
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
int init_ramdisk ( struct ramdisk *ramdisk, userptr_t data, size_t len,
|
||||||
|
unsigned int blksize ) {
|
||||||
|
|
||||||
|
if ( ! blksize )
|
||||||
|
blksize = 512;
|
||||||
|
|
||||||
|
ramdisk->data = data;
|
||||||
|
ramdisk->blockdev.read = ramdisk_read;
|
||||||
|
ramdisk->blockdev.write = ramdisk_write;
|
||||||
|
ramdisk->blockdev.blksize = blksize;
|
||||||
|
ramdisk->blockdev.blocks = ( len / blksize );
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
Reference in New Issue