qemu-e2k/pc-bios/optionrom/optionrom.h
Paolo Bonzini cdebec5e40 linuxboot: compute initrd loading address
Even though hw/i386/pc.c tries to compute a valid loading address for the
initrd, close to the top of RAM, this does not take into account other
data that is malloced into that memory by SeaBIOS.

Luckily we can easily look at the memory map to find out how much memory is
used up there.  This patch places the initrd in the first four gigabytes,
below the first hole (as returned by INT 15h, AX=e801h).

Without this patch:
[    0.000000] init_memory_mapping: [mem 0x07000000-0x07fdffff]
[    0.000000] RAMDISK: [mem 0x0710a000-0x07fd7fff]

With this patch:
[    0.000000] init_memory_mapping: [mem 0x07000000-0x07fdffff]
[    0.000000] RAMDISK: [mem 0x07112000-0x07fdffff]

So linuxboot is able to use the 64k that were added as padding for
QEMU <= 2.1.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-09 15:36:15 +02:00

153 lines
3.7 KiB
C

/*
* Common Option ROM Functions
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Copyright Novell Inc, 2009
* Authors: Alexander Graf <agraf@suse.de>
*/
#define NO_QEMU_PROTOS
#include "../../include/hw/nvram/fw_cfg.h"
#define BIOS_CFG_IOPORT_CFG 0x510
#define BIOS_CFG_IOPORT_DATA 0x511
/* Break the translation block flow so -d cpu shows us values */
#define DEBUG_HERE \
jmp 1f; \
1:
/*
* Read a variable from the fw_cfg device.
* Clobbers: %edx
* Out: %eax
*/
.macro read_fw VAR
mov $\VAR, %ax
mov $BIOS_CFG_IOPORT_CFG, %dx
outw %ax, (%dx)
mov $BIOS_CFG_IOPORT_DATA, %dx
inb (%dx), %al
shl $8, %eax
inb (%dx), %al
shl $8, %eax
inb (%dx), %al
shl $8, %eax
inb (%dx), %al
bswap %eax
.endm
#define read_fw_blob_pre(var) \
read_fw var ## _SIZE; \
mov %eax, %ecx; \
mov $var ## _DATA, %ax; \
mov $BIOS_CFG_IOPORT_CFG, %edx; \
outw %ax, (%dx); \
mov $BIOS_CFG_IOPORT_DATA, %dx; \
cld
/*
* Read a blob from the fw_cfg device.
* Requires _ADDR, _SIZE and _DATA values for the parameter.
*
* Clobbers: %eax, %edx, %es, %ecx, %edi
*/
#define read_fw_blob(var) \
read_fw var ## _ADDR; \
mov %eax, %edi; \
read_fw_blob_pre(var); \
/* old as(1) doesn't like this insn so emit the bytes instead: \
rep insb (%dx), %es:(%edi); \
*/ \
.dc.b 0xf3,0x6c
/*
* Read a blob from the fw_cfg device in forced addr32 mode.
* Requires _ADDR, _SIZE and _DATA values for the parameter.
*
* Clobbers: %eax, %edx, %es, %ecx, %edi
*/
#define read_fw_blob_addr32(var) \
read_fw var ## _ADDR; \
mov %eax, %edi; \
read_fw_blob_pre(var); \
/* old as(1) doesn't like this insn so emit the bytes instead: \
addr32 rep insb (%dx), %es:(%edi); \
*/ \
.dc.b 0x67,0xf3,0x6c
/*
* Read a blob from the fw_cfg device in forced addr32 mode, address is in %edi.
* Requires _SIZE and _DATA values for the parameter.
*
* Clobbers: %eax, %edx, %edi, %es, %ecx
*/
#define read_fw_blob_addr32_edi(var) \
read_fw_blob_pre(var); \
/* old as(1) doesn't like this insn so emit the bytes instead: \
addr32 rep insb (%dx), %es:(%edi); \
*/ \
.dc.b 0x67,0xf3,0x6c
#define OPTION_ROM_START \
.code16; \
.text; \
.global _start; \
_start:; \
.short 0xaa55; \
.byte (_end - _start) / 512;
#define BOOT_ROM_START \
OPTION_ROM_START \
lret; \
.org 0x18; \
.short 0; \
.short _pnph; \
_pnph: \
.ascii "$PnP"; \
.byte 0x01; \
.byte ( _pnph_len / 16 ); \
.short 0x0000; \
.byte 0x00; \
.byte 0x00; \
.long 0x00000000; \
.short _manufacturer; \
.short _product; \
.long 0x00000000; \
.short 0x0000; \
.short 0x0000; \
.short _bev; \
.short 0x0000; \
.short 0x0000; \
.equ _pnph_len, . - _pnph; \
_bev:; \
/* DS = CS */ \
movw %cs, %ax; \
movw %ax, %ds;
#define OPTION_ROM_END \
.byte 0; \
.align 512, 0; \
_end:
#define BOOT_ROM_END \
_manufacturer:; \
.asciz "QEMU"; \
_product:; \
.asciz BOOT_ROM_PRODUCT; \
OPTION_ROM_END