qemu/pc-bios/optionrom/optionrom.h
Marcus Hähnel 48972f8cad optionrom: add a DMA-enabled multiboot ROM
Add a new option rom for the multiboot loader, using DMA transfers to copy
data instead of "rep insb".

This significantly lowers QEMU's startup latency by a factor of about 40,
for example, going from 30sec to 0.8sec when loading modules of 120MB
in size.

Signed-off-by: Marcus Hähnel <marcus.haehnel@kernkonzept.com>
Signed-off-by: Adam Lackorzynski <adam@l4re.org>
[Modified to keep the non-DMA code depending on #ifdef USE_FW_CFG_DMA;
 do not write below stack. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-02 15:57:27 +01:00

231 lines
5.6 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 FW_CFG_KERNEL_ADDR 0x07
#define FW_CFG_KERNEL_SIZE 0x08
#define FW_CFG_KERNEL_CMDLINE 0x09
#define FW_CFG_INITRD_ADDR 0x0a
#define FW_CFG_INITRD_SIZE 0x0b
#define FW_CFG_KERNEL_ENTRY 0x10
#define FW_CFG_KERNEL_DATA 0x11
#define FW_CFG_INITRD_DATA 0x12
#define FW_CFG_CMDLINE_ADDR 0x13
#define FW_CFG_CMDLINE_SIZE 0x14
#define FW_CFG_CMDLINE_DATA 0x15
#define FW_CFG_SETUP_ADDR 0x16
#define FW_CFG_SETUP_SIZE 0x17
#define FW_CFG_SETUP_DATA 0x18
#define BIOS_CFG_IOPORT_CFG 0x510
#define BIOS_CFG_IOPORT_DATA 0x511
#define FW_CFG_DMA_CTL_ERROR 0x01
#define FW_CFG_DMA_CTL_READ 0x02
#define FW_CFG_DMA_CTL_SKIP 0x04
#define FW_CFG_DMA_CTL_SELECT 0x08
#define FW_CFG_DMA_CTL_WRITE 0x10
#define FW_CFG_DMA_SIGNATURE 0x51454d5520434647ULL /* "QEMU CFG" */
#define BIOS_CFG_DMA_ADDR_HIGH 0x514
#define BIOS_CFG_DMA_ADDR_LOW 0x518
/* 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
/*
* Read data from the fw_cfg device using DMA.
* Clobbers: %edx, %eax, ADDR, SIZE, memory[%esp-16] to memory[%esp]
*/
.macro read_fw_dma VAR, SIZE, ADDR
/* Address */
bswapl \ADDR
pushl \ADDR
/* We only support 32 bit target addresses */
xorl %eax, %eax
pushl %eax
mov $BIOS_CFG_DMA_ADDR_HIGH, %dx
outl %eax, (%dx)
/* Size */
bswapl \SIZE
pushl \SIZE
/* Control */
movl $(\VAR << 16) | (FW_CFG_DMA_CTL_READ | FW_CFG_DMA_CTL_SELECT), %eax
bswapl %eax
pushl %eax
movl %esp, %eax /* Address of the struct we generated */
bswapl %eax
mov $BIOS_CFG_DMA_ADDR_LOW, %dx
outl %eax, (%dx) /* Initiate DMA */
1: mov (%esp), %eax /* Wait for completion */
bswapl %eax
testl $~FW_CFG_DMA_CTL_ERROR, %eax
jnz 1b
addl $16, %esp
.endm
/*
* Read a blob from the fw_cfg device using DMA
* Requires _ADDR, _SIZE and _DATA values for the parameter.
*
* Clobbers: %eax, %edx, %es, %ecx, %edi and adresses %esp-20 to %esp
*/
#ifdef USE_FW_CFG_DMA
#define read_fw_blob_dma(var) \
read_fw var ## _SIZE; \
mov %eax, %ecx; \
read_fw var ## _ADDR; \
mov %eax, %edi ;\
read_fw_dma var ## _DATA, %ecx, %edi
#else
#define read_fw_blob_dma(var) read_fw_blob(var)
#endif
#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