[Qemu-devel] [PATCH 1/2] extboot: add option rom.

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <address@hidden>
---
 Makefile                    |    2 +-
 pc-bios/optionrom/Makefile  |    2 +-
 pc-bios/optionrom/extboot.S |  695 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 697 insertions(+), 2 deletions(-)
 create mode 100644 pc-bios/optionrom/extboot.S

diff --git a/Makefile b/Makefile
index 2e0b85c..104351e 100644
--- a/Makefile
+++ b/Makefile
@@ -212,7 +212,7 @@ BLOBS=bios.bin vgabios.bin vgabios-cirrus.bin ppc_rom.bin \
 video.x openbios-sparc32 openbios-sparc64 openbios-ppc \
 pxe-ne2k_pci.bin pxe-rtl8139.bin pxe-pcnet.bin pxe-e1000.bin \
 bamboo.dtb petalogix-s3adsp1800.dtb \
-multiboot.bin
+multiboot.bin extboot.bin
 else
 BLOBS=
 endif
diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
index 1d84c07..840c895 100644
--- a/pc-bios/optionrom/Makefile
+++ b/pc-bios/optionrom/Makefile
@@ -11,7 +11,7 @@ CFLAGS = -Wall -Wstrict-prototypes -Werror 
-fomit-frame-pointer -fno-builtin
 CFLAGS += -I$(SRC_PATH)
 CFLAGS += $(call cc-option, $(CFLAGS), -fno-stack-protector,"")
 
-build-all: multiboot.bin
+build-all: multiboot.bin extboot.bin
 
 %.img: %.o
        $(call quiet-command,$(LD) -Ttext 0 -e _start -s -o $@ $<,"  Building 
$(TARGET_DIR)$@")
diff --git a/pc-bios/optionrom/extboot.S b/pc-bios/optionrom/extboot.S
new file mode 100644
index 0000000..1e60f68
--- /dev/null
+++ b/pc-bios/optionrom/extboot.S
@@ -0,0 +1,695 @@
+/*
+ * 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 <address@hidden>
+ */
+
+.code16
+.text
+       .global _start
+_start:
+       .short 0xaa55
+       .byte (_end - _start) / 512
+       push %eax
+       push %ds
+
+       /* setup ds so we can access the IVT */
+       xor %ax, %ax
+       mov %ax, %ds
+
+       /* there is one more bootable HD */
+       incb 0x0475
+
+       /* save old int 19 */
+       mov (0x19*4), %eax
+       mov %eax, %cs:old_int19
+
+       /* install out int 19 handler */
+       movw $int19_handler, (0x19*4)
+       mov %cs, (0x19*4+2)
+
+       pop %ds
+       pop %eax
+       lret
+
+int19_handler:
+       push %eax
+       push %bx
+       push %cx
+       push %dx
+       push %ds
+
+       /* setup ds to access IVT */
+       xor %ax, %ax
+       mov %ax, %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 */
+       /* save old int 13 to int 2c */
+       mov (0x13*4), %eax
+       mov %eax, %cs:old_int13
+
+       /* install our int 13 handler */
+       movw $int13_handler, (0x13*4)
+       mov %cs, (0x13*4+2)
+       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 */
+       /* restore previous int $0x19 handler */
+       mov %cs:old_int19,%eax
+       mov %eax,(0x19*4)
+       
+       pop %ds
+       pop %dx
+       pop %cx
+       pop %bx
+       pop %eax
+       ljmpw *%cs:old_int19
+
+#define FLAGS_CF       0x01
+
+/* The two macro below clear/set the carry flag to indicate the status
+ * of the interrupt execution. It is not enough to issue a clc/stc instruction,
+ * since the value of the flags register will be overwritten by whatever is
+ * in the stack frame
+ */
+.macro clc_stack
+       push %bp
+       mov %sp, %bp
+       /* 8 = 2 (bp, just pushed) + 2 (ip) + 3 (real mode interrupt frame) */
+       and $(~FLAGS_CF), 8(%bp)
+       pop %bp
+.endm
+
+.macro stc_stack
+       push %bp
+       /* 8 = 2 (bp, just pushed) + 2 (ip) + 3 (real mode interrupt frame) */
+       or $(FLAGS_CF), 8(%bp)
+       pop %bp
+.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_stack
+       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 $16
+
+       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_stack
+       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 $16
+
+       /* 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_stack
+       ret
+
+alternate_disk_reset:
+       movb $0, %ah
+       clc_stack
+       ret
+
+read_disk_drive_size:
+       push %bx
+       alloca $16
+
+       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_stack
+       ret
+
+check_if_extensions_present:
+       mov $0x30, %ah
+       mov $0xAA55, %bx
+       mov $0x07, %cx
+       clc_stack
+       ret
+
+.macro extended_read_write_sectors cmd
+       cmpb $10, 0(%si)
+       jg 1f
+       mov $1, %ah
+       stc_stack
+       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_stack
+       ret
+.endm
+
+extended_read_sectors:
+       extended_read_write_sectors $0x01
+
+extended_write_sectors:
+       extended_read_write_sectors $0x02
+
+get_extended_drive_parameters:
+       push %ax
+       push %bp
+       push %cx
+       push %dx
+
+       allocbpa $16
+
+       movw $0, 0(%bp) /* read c,h,s */
+       push %bp
+       call send_command
+       add $2, %sp
+
+       /* write size */
+       movw $26, 0(%si)
+
+       /* 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)
+
+       /* set total number of sectors */
+       mov 8(%bp), %ax
+       mov %ax, 16(%si)
+       mov 10(%bp), %ax
+       mov %ax, 18(%si)
+       mov 12(%bp), %ax
+       mov %ax, 20(%si)
+       mov 14(%bp), %ax
+       mov %ax, 22(%si)
+
+       /* number of bytes per sector */
+       movw $512, 24(%si)
+
+       freebpa
+
+       pop %dx
+       pop %cx
+       pop %bp
+       pop %ax
+
+       mov $0, %ah
+       clc_stack
+       ret
+
+terminate_disk_emulation:
+       mov $1, %ah
+       stc_stack
+       ret
+
+int13_handler:
+       cmp $0x80, %dl
+       je 1f
+       ljmpw *%cs:old_int13
+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
+
+/* Variables */
+.align 4, 0
+old_int13:     .long 0
+old_int19:     .long 0
+       
+.align 512, 0
+_end:
-- 
1.6.2.5