From 3382568ee1663ec250b165c823081220e2d05ee0 Mon Sep 17 00:00:00 2001 From: Anthony Liguori Date: Wed, 2 Jan 2008 10:22:29 -0600 Subject: [PATCH] kvm: extboot: add extboot to kvm-userspace extboot is an x86 Option ROM that passes through int13 functions to a VMM which allows a VMM to expose an arbitrary block device as the primary BIOS disk. It can be used to boot SCSI or paravirtual devices. Signed-off-by: Anthony Liguori Signed-off-by: Avi Kivity --- kvm/extboot/Makefile | 21 ++ kvm/extboot/STATUS | 6 + kvm/extboot/extboot.S | 742 ++++++++++++++++++++++++++++++++++++++++++++++++++ kvm/extboot/signrom.c | 79 ++++++ 4 files changed, 848 insertions(+) create mode 100644 kvm/extboot/Makefile create mode 100644 kvm/extboot/STATUS create mode 100644 kvm/extboot/extboot.S create mode 100644 kvm/extboot/signrom.c diff --git a/kvm/extboot/Makefile b/kvm/extboot/Makefile new file mode 100644 index 0000000000..1ea71a735d --- /dev/null +++ b/kvm/extboot/Makefile @@ -0,0 +1,21 @@ +OBJCOPY=objcopy + +CFLAGS=-Wall -Wstrict-prototypes -Werror -fomit-frame-pointer -fno-builtin \ + -fno-stack-protector + +all: extboot.bin + +%.o: %.S + $(CC) $(CFLAGS) -o $@ -c $< + +extboot.img: extboot.o + $(LD) --oformat binary -Ttext 0 -o $@ $< + +extboot.bin: extboot.img signrom + ./signrom extboot.img extboot.bin + +signrom: signrom.c + $(CC) -o $@ -g -Wall $^ + +clean: + $(RM) *.o *.img *.bin signrom *~ diff --git a/kvm/extboot/STATUS b/kvm/extboot/STATUS new file mode 100644 index 0000000000..687c6d64ce --- /dev/null +++ b/kvm/extboot/STATUS @@ -0,0 +1,6 @@ +Working +------- + +Ubuntu Server 7.04 (i386) +Windows 2000 Professional (i386) +Windows XP SP2 (i386) diff --git a/kvm/extboot/extboot.S b/kvm/extboot/extboot.S new file mode 100644 index 0000000000..584d36d560 --- /dev/null +++ b/kvm/extboot/extboot.S @@ -0,0 +1,742 @@ +/* + * Extended Boot Option ROM + * + * 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 + * (at your option) 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright IBM Corporation, 2007 + * Authors: Anthony Liguori + */ + +.code16 +.text + .global _start +_start: + .short 0xaa55 + .byte (_end - _start) / 512 + push %ax + push %bx + push %cx + push %dx + push %ds + + /* setup ds so we can access the IVT */ + xor %ax, %ax + mov %ax, %ds + + /* save old int 19 at int 2b */ + mov $(0x19 * 4), %bx + mov 0(%bx), %ax + mov 2(%bx), %cx + + mov $(0x2b * 4), %bx + mov %ax, 0(%bx) + mov %cx, 2(%bx) + + /* install out int 19 handler */ + mov $(0x19 * 4), %bx + mov $int19_handler, %ax + mov %ax, 0(%bx) + mov %cs, 2(%bx) + + pop %ds + pop %dx + pop %cx + pop %bx + pop %ax + lret + +int19_handler: + push %ax + push %bx + push %cx + push %dx + push %ds + + movw $0x404, %dx + inb %dx, %al + cmp $1, %al + je 1f + cmp $2, %al + je 2f + jmp 3f + +1: /* hook int13: intb(0x404) == 1 */ + /* setup ds to access IVT */ + xor %ax, %ax + mov %ax, %ds + + /* save old int 13 to int 2c */ + mov $(0x13 * 4), %bx + mov 0(%bx), %ax + mov 2(%bx), %cx + + mov $(0x2c * 4), %bx + mov %ax, 0(%bx) + mov %cx, 2(%bx) + + /* install our int 13 handler */ + mov $(0x13 * 4), %bx + mov $int13_handler, %ax + + mov %ax, 0(%bx) + mov %cs, 2(%bx) + jmp 3f + +2: /* linux boot: intb(0x404) == 2 */ + cli + cld + mov $0x9000, %ax + mov %ax, %ds + mov %ax, %es + mov %ax, %fs + mov %ax, %gs + mov %ax, %ss + mov $0x8ffe, %sp + ljmp $0x9000 + 0x20, $0 + +3: /* fall through: inb(0x404) == 0 */ + pop %ds + pop %dx + pop %cx + pop %bx + pop %ax + int $0x2b + +#define FLAGS_CF 0x01 + +.macro clc + push %ax + pushf + pop %ax + and $(~FLAGS_CF), %ax + push %ax + popf + pop %ax +.endm + +.macro stc + push %ax + pushf + pop %ax + or $(FLAGS_CF), %ax + push %ax + popf + pop %ax +.endm + +/* we clobber %bx */ +.macro alloca size + push %ds + push %bp + mov %sp, %bp /* remember the current stack position */ + + mov %ss, %bx + mov %bx, %ds + + sub \size, %sp + and $(~0x0F), %sp + mov %sp, %bx + + push %bp + mov 0(%bp), %bp +.endm + +/* we clobber %bp */ +.macro allocbpa size + mov %sp, %bp /* remember the current stack position */ + sub \size, %sp + and $(~0x0F), %sp + push %bp + mov %sp, %bp + add $2, %bp +.endm + +.macro freea + pop %sp + add $2, %sp + pop %ds +.endm + +.macro freebpa + pop %sp +.endm + +.macro dump reg + push %ax + push %dx + + mov \reg, %ax + mov $0x406, %dx + outw %ax, %dx + + pop %dx + pop %ax +.endm + +.macro callout value + push %bp + push %bx + mov %sp, %bp + alloca $16 + push %ax + push %dx + + mov %ax, 0(%bx) /* ax */ + mov 0(%bp), %ax /* bx */ + mov %ax, 2(%bx) + mov %cx, 4(%bx) /* cx */ + mov %dx, 6(%bx) /* dx */ + mov %si, 8(%bx) /* si */ + mov %ds, 10(%bx) /* ds */ + mov %es, 12(%bx) /* ds */ + movw \value, 14(%bx) /* value */ + + mov %bx, %ax + shr $4, %ax + mov %ds, %dx + add %dx, %ax + + mov $0x407, %dx + outw %ax, %dx + + pop %dx + pop %ax + freea + pop %bx + pop %bp +.endm + +send_command: + push %bp + mov %sp, %bp + push %ax + push %bx + push %dx + + mov 4(%bp), %ax + shr $4, %ax + and $0x0FFF, %ax + mov %ss, %bx + add %bx, %ax + + mov $0x405, %dx + outw %ax, %dx + + pop %dx + pop %bx + pop %ax + pop %bp + + push %ax + mov 2(%bx), %ax + pop %ax + + ret + +add32: /* lo, hi, lo, hi */ + push %bp + mov %sp, %bp + + movw 4(%bp), %cx /* hi */ + movw 6(%bp), %dx /* lo */ + + add 10(%bp), %dx + jnc 1f + add $1, %cx +1: add 8(%bp), %cx + + pop %bp + ret + +mul32: /* lo, hi, lo, hi */ + /* 10(%bp), 8(%bp), 6(%bp), 4(%bp) */ + push %bp + mov %sp, %bp + push %ax + push %bx + + xor %cx, %cx + xor %dx, %dx + + /* for (i = 0; i < 16;) */ + xor %bx, %bx +0: + cmp $16, %bx + jge 2f + + mov 6(%bp), %ax + and $1, %ax + cmp $1, %ax + jne 1f + push 10(%bp) + push 8(%bp) + push %dx + push %cx + call add32 + add $8, %sp +1: + shlw $1, 8(%bp) + movw 10(%bp), %ax + and $0x8000, %ax + cmp $0x8000, %ax + jne 1f + orw $1, 8(%bp) +1: + shlw $1, 10(%bp) + shrw $1, 6(%bp) + + /* i++) { */ + add $1, %bx + jmp 0b + +2: + pop %bx + pop %ax + pop %bp + ret + +disk_reset: + movb $0, %ah + clc + ret + +/* this really should be a function, not a macro but i'm lazy */ +.macro read_write_disk_sectors cmd + push %ax + push %bx + push %cx + push %dx + push %si + + push %bp + sub $10, %sp + mov %sp, %bp + + /* save nb_sectors */ + mov %al, 6(%bp) + movb $0, 7(%bp) + + /* save buffer */ + mov %bx, 8(%bp) + + /* cylinders */ + xor %ax, %ax + mov %cl, %al + shl $2, %ax + and $0x300, %ax + mov %ch, %al + mov %ax, 0(%bp) + + /* heads */ + xor %ax, %ax + mov %dh, %al + mov %ax, 2(%bp) + + /* sectors - 1 */ + xor %ax, %ax + mov %cl, %al + and $0x3F, %al + sub $1, %ax + mov %ax, 4(%bp) + + alloca $8 + + movw $0, 0(%bx) /* read c,h,s */ + push %bx + call send_command + add $2, %sp + + mov 6(%bx), %ax /* total_sectors */ + mov 2(%bp), %si /* *= heads */ + mul %si + add 4(%bp), %ax /* += sectors - 1 */ + + push 4(%bx) /* total_heads */ + push $0 + push 6(%bx) /* total_sectors */ + push $0 + call mul32 + add $8, %sp + + push 0(%bp) /* cylinders */ + push $0 + push %dx + push %cx + call mul32 + add $8, %sp + + add %ax, %dx + jnc 1f + add $1, %cx +1: + freea + + alloca $16 + + movw \cmd, 0(%bx) /* read */ + movw 6(%bp), %ax /* nb_sectors */ + movw %ax, 2(%bx) + movw %es, 4(%bx) /* segment */ + movw 8(%bp), %ax /* offset */ + mov %ax, 6(%bx) + movw %dx, 8(%bx) /* sector */ + movw %cx, 10(%bx) + movw $0, 12(%bx) + movw $0, 14(%bx) + + push %bx + call send_command + add $2, %sp + + freea + + add $10, %sp + pop %bp + + pop %si + pop %dx + pop %cx + pop %bx + pop %ax + + mov $0, %ah + clc + ret +.endm + +read_disk_sectors: + read_write_disk_sectors $0x01 + +write_disk_sectors: + read_write_disk_sectors $0x02 + +read_disk_drive_parameters: + push %bx + + /* allocate memory for packet, pointer gets returned in bx */ + alloca $8 + + /* issue command */ + movw $0, 0(%bx) /* cmd = 0, read c,h,s */ + push %bx + call send_command + add $2, %sp + + /* normalize sector value */ + movb 6(%bx), %cl + andb $0x3F, %cl + movb %cl, 6(%bx) + + /* normalize cylinders */ + subw $2, 2(%bx) + + /* normalize heads */ + subw $1, 4(%bx) + + /* return code */ + mov $0, %ah + + /* cylinders */ + movb 2(%bx), %ch + movb 3(%bx), %cl + shlb $6, %cl + andb $0xC0, %cl + + /* sectors */ + orb 6(%bx), %cl + + /* heads */ + movb 4(%bx), %dh + + /* drives */ + movb $1, %dl + + /* status */ + mov $0, %ah + + freea + + pop %bx + + /* do this last since it's the most sensitive */ + clc + ret + +alternate_disk_reset: + movb $0, %ah + clc + ret + +read_disk_drive_size: + push %bx + alloca $8 + + movw $0, 0(%bx) /* cmd = 0, read c,h,s */ + push %bx + call send_command + add $2, %sp + + /* cylinders - 1 to cx:dx */ + mov 2(%bx), %dx + xor %cx, %cx + sub $1, %dx + + /* heads */ + push 4(%bx) + push $0 + push %dx + push %cx + call mul32 + add $8, %sp + + /* sectors */ + push 6(%bx) + push $0 + push %dx + push %cx + call mul32 + add $8, %sp + + /* status */ + mov $3, %ah + + freea + pop %bx + + clc + ret + +check_if_extensions_present: + mov $0x30, %ah + mov $0xAA55, %bx + mov $0x07, %cx + clc + ret + +.macro extended_read_write_sectors cmd + cmpb $10, 0(%si) + jg 1f + mov $1, %ah + stc + ret +1: + push %ax + push %bp + allocbpa $16 + + movw \cmd, 0(%bp) /* read */ + movw 2(%si), %ax /* nb_sectors */ + movw %ax, 2(%bp) + movw 4(%si), %ax /* offset */ + movw %ax, 6(%bp) + movw 6(%si), %ax /* segment */ + movw %ax, 4(%bp) + movw 8(%si), %ax /* block */ + movw %ax, 8(%bp) + movw 10(%si), %ax + movw %ax, 10(%bp) + movw 12(%si), %ax + movw %ax, 12(%bp) + movw 14(%si), %ax + movw %ax, 14(%bp) + + push %bp + call send_command + add $2, %sp + + freebpa + pop %bp + pop %ax + + mov $0, %ah + clc + ret +.endm + +extended_read_sectors: + extended_read_write_sectors $0x01 + +extended_write_sectors: + extended_read_write_sectors $0x02 + +get_extended_drive_parameters: + mov $1, %ah + stc + ret +#if 0 + /* this function is seriously borked */ +1: + push %ax + push %bp + push %cx + push %dx + + allocbpa $8 + + movw $0, 0(%bp) /* read c,h,s */ + push %bp + call send_command + add $2, %sp + + /* check the size of the passed in data */ + cmpw $26, 0(%si) + mov 0(%si), %ax + dump %ax + jle 0b + + /* set flags to 2 */ + movw $2, 2(%si) + + /* cylinders */ + mov 2(%bp), %ax + mov %ax, 4(%si) + xor %ax, %ax + mov %ax, 6(%si) + + /* heads */ + mov 4(%bp), %ax + mov %ax, 8(%si) + xor %ax, %ax + mov %ax, 10(%si) + + /* sectors */ + mov 6(%bp), %ax + mov %ax, 12(%si) + xor %ax, %ax + mov %ax, 14(%si) + + /* calculate total sectors */ + + /* cx:dx = cylinders */ + mov 2(%bp), %dx + xor %cx, %cx + + /* *= heads */ + push 4(%bp) + push $0 + push %dx + push %cx + call mul32 + add $8, %sp + + /* *= sectors */ + push 6(%bp) + push $0 + push %dx + push %cx + call mul32 + add $8, %sp + + /* total number of sectors */ + mov %dx, 16(%si) + mov %cx, 18(%si) + xor %ax, %ax + mov %ax, 20(%si) + mov %ax, 22(%si) + + /* number of bytes per sector */ + movw $512, 24(%si) + + /* optional segmention:offset to EDD config */ + cmpw $30, 0(%si) + jl 1f + + movw $0xFFFF, 26(%si) + movw $0xFFFF, 28(%si) + +1: + freebpa + + pop %dx + pop %cx + pop %bp + pop %ax + + mov $0, %ah + clc + ret +#endif + +terminate_disk_emulation: + mov $1, %ah + stc + ret + +int13_handler: + cmp $0x80, %dl + je 1f + int $0x2c + iret +1: + cmp $0x0, %ah + jne 1f + call disk_reset + iret +1: + cmp $0x2, %ah + jne 1f + call read_disk_sectors + iret +1: + cmp $0x8, %ah + jne 1f + call read_disk_drive_parameters + iret +1: + cmp $0x15, %ah + jne 1f + call read_disk_drive_size + iret +1: + cmp $0x41, %ah + jne 1f + call check_if_extensions_present + iret +1: + cmp $0x42, %ah + jne 1f + call extended_read_sectors + iret +1: + cmp $0x48, %ah + jne 1f + call get_extended_drive_parameters + iret +1: + cmp $0x4b, %ah + jne 1f + call terminate_disk_emulation + iret +1: + cmp $0x0d, %ah + jne 1f + call alternate_disk_reset + iret +1: + cmp $0x03, %ah + jne 1f + call write_disk_sectors + iret +1: + cmp $0x43, %ah + jne 1f + call extended_write_sectors + iret +1: + int $0x18 /* boot failed */ + iret + +.align 512, 0 +_end: diff --git a/kvm/extboot/signrom.c b/kvm/extboot/signrom.c new file mode 100644 index 0000000000..fe8d677459 --- /dev/null +++ b/kvm/extboot/signrom.c @@ -0,0 +1,79 @@ +/* + * Extended Boot Option ROM + * + * 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 + * (at your option) 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright IBM Corporation, 2007 + * Authors: Anthony Liguori + */ + +#include +#include +#include + +int main(int argc, char **argv) +{ + FILE *fin, *fout; + char buffer[512], oldbuffer[512]; + int i, size, lag = 0; + uint8_t sum = 0; + + if (argc != 3) { + printf("Usage: %s ROM OUTPUT\n", argv[0]); + return 1; + } + + fin = fopen(argv[1], "rb"); + fout = fopen(argv[2], "wb"); + + if (fin == NULL || fout == NULL) { + fprintf(stderr, "Could not open input/output files\n"); + return 1; + } + + do { + size = fread(buffer, 512, 1, fin); + if (size == 1) { + for (i = 0; i < 512; i++) + sum += buffer[i]; + + if (lag) { + if (fwrite(oldbuffer, 512, 1, fout) != 1) { + fprintf(stderr, "Write failed\n"); + return 1; + } + } + lag = 1; + memcpy(oldbuffer, buffer, 512); + } + } while (size == 1); + + if (size != 0) { + fprintf(stderr, "Failed to read from input file\n"); + return 1; + } + + oldbuffer[511] = -sum; + + if (fwrite(oldbuffer, 512, 1, fout) != 1) { + fprintf(stderr, "Failed to write to output file\n"); + return 1; + } + + fclose(fin); + fclose(fout); + + return 0; +} -- 2.11.4.GIT