mirror of https://gitee.com/openkylin/qemu.git
Convert linux bootrom to external rom and fw_cfg
We already have a working multiboot implementation that uses fw_cfg to get its kernel module etc. data in int19 runtime now. So what's missing is a working linux boot option rom. While at it I figured it would be a good idea to take the opcode generator out of pc.c and instead use a proper option rom, like we do with multiboot. So here it is - an fw_cfg using option rom for -kernel with linux! Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Alexander Graf
Anthony Liguori
parent
dd4b2659cd
commit
57a46d0579
|
|
@ -20,7 +20,13 @@
|
|||
#define FW_CFG_KERNEL_ENTRY 0x10
|
||||
#define FW_CFG_KERNEL_DATA 0x11
|
||||
#define FW_CFG_INITRD_DATA 0x12
|
||||
#define FW_CFG_MAX_ENTRY 0x13
|
||||
#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 FW_CFG_MAX_ENTRY 0x19
|
||||
|
||||
#define FW_CFG_WRITE_CHANNEL 0x4000
|
||||
#define FW_CFG_ARCH_LOCAL 0x8000
|
||||
|
|
|
|||
122
hw/pc.c
122
hw/pc.c
|
|
@ -487,85 +487,6 @@ static void *bochs_bios_init(void)
|
|||
return fw_cfg;
|
||||
}
|
||||
|
||||
/* Generate an initial boot sector which sets state and jump to
|
||||
a specified vector */
|
||||
static void generate_bootsect(uint32_t gpr[8], uint16_t segs[6], uint16_t ip)
|
||||
{
|
||||
uint8_t rom[512], *p, *reloc;
|
||||
uint8_t sum;
|
||||
int i;
|
||||
|
||||
memset(rom, 0, sizeof(rom));
|
||||
|
||||
p = rom;
|
||||
/* Make sure we have an option rom signature */
|
||||
*p++ = 0x55;
|
||||
*p++ = 0xaa;
|
||||
|
||||
/* ROM size in sectors*/
|
||||
*p++ = 1;
|
||||
|
||||
/* Hook int19 */
|
||||
|
||||
*p++ = 0x50; /* push ax */
|
||||
*p++ = 0x1e; /* push ds */
|
||||
*p++ = 0x31; *p++ = 0xc0; /* xor ax, ax */
|
||||
*p++ = 0x8e; *p++ = 0xd8; /* mov ax, ds */
|
||||
|
||||
*p++ = 0xc7; *p++ = 0x06; /* movvw _start,0x64 */
|
||||
*p++ = 0x64; *p++ = 0x00;
|
||||
reloc = p;
|
||||
*p++ = 0x00; *p++ = 0x00;
|
||||
|
||||
*p++ = 0x8c; *p++ = 0x0e; /* mov cs,0x66 */
|
||||
*p++ = 0x66; *p++ = 0x00;
|
||||
|
||||
*p++ = 0x1f; /* pop ds */
|
||||
*p++ = 0x58; /* pop ax */
|
||||
*p++ = 0xcb; /* lret */
|
||||
|
||||
/* Actual code */
|
||||
*reloc = (p - rom);
|
||||
|
||||
*p++ = 0xfa; /* CLI */
|
||||
*p++ = 0xfc; /* CLD */
|
||||
|
||||
for (i = 0; i < 6; i++) {
|
||||
if (i == 1) /* Skip CS */
|
||||
continue;
|
||||
|
||||
*p++ = 0xb8; /* MOV AX,imm16 */
|
||||
*p++ = segs[i];
|
||||
*p++ = segs[i] >> 8;
|
||||
*p++ = 0x8e; /* MOV <seg>,AX */
|
||||
*p++ = 0xc0 + (i << 3);
|
||||
}
|
||||
|
||||
for (i = 0; i < 8; i++) {
|
||||
*p++ = 0x66; /* 32-bit operand size */
|
||||
*p++ = 0xb8 + i; /* MOV <reg>,imm32 */
|
||||
*p++ = gpr[i];
|
||||
*p++ = gpr[i] >> 8;
|
||||
*p++ = gpr[i] >> 16;
|
||||
*p++ = gpr[i] >> 24;
|
||||
}
|
||||
|
||||
*p++ = 0xea; /* JMP FAR */
|
||||
*p++ = ip; /* IP */
|
||||
*p++ = ip >> 8;
|
||||
*p++ = segs[1]; /* CS */
|
||||
*p++ = segs[1] >> 8;
|
||||
|
||||
/* sign rom */
|
||||
sum = 0;
|
||||
for (i = 0; i < (sizeof(rom) - 1); i++)
|
||||
sum += rom[i];
|
||||
rom[sizeof(rom) - 1] = -sum;
|
||||
|
||||
rom_add_blob("linux-bootsect", rom, sizeof(rom),
|
||||
PC_ROM_MIN_OPTION, PC_ROM_MAX, PC_ROM_ALIGN);
|
||||
}
|
||||
|
||||
static long get_file_size(FILE *f)
|
||||
{
|
||||
long where, size;
|
||||
|
|
@ -812,12 +733,9 @@ static void load_linux(void *fw_cfg,
|
|||
target_phys_addr_t max_ram_size)
|
||||
{
|
||||
uint16_t protocol;
|
||||
uint32_t gpr[8];
|
||||
uint16_t seg[6];
|
||||
uint16_t real_seg;
|
||||
int setup_size, kernel_size, initrd_size = 0, cmdline_size;
|
||||
uint32_t initrd_max;
|
||||
uint8_t header[8192], *setup, *kernel;
|
||||
uint8_t header[8192], *setup, *kernel, *initrd_data;
|
||||
target_phys_addr_t real_addr, prot_addr, cmdline_addr, initrd_addr = 0;
|
||||
FILE *f;
|
||||
char *vmode;
|
||||
|
|
@ -886,9 +804,11 @@ static void load_linux(void *fw_cfg,
|
|||
if (initrd_max >= max_ram_size-ACPI_DATA_SIZE)
|
||||
initrd_max = max_ram_size-ACPI_DATA_SIZE-1;
|
||||
|
||||
/* kernel command line */
|
||||
rom_add_blob_fixed("cmdline", kernel_cmdline,
|
||||
strlen(kernel_cmdline)+1, cmdline_addr);
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_ADDR, cmdline_addr);
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE, strlen(kernel_cmdline)+1);
|
||||
fw_cfg_add_bytes(fw_cfg, FW_CFG_CMDLINE_DATA,
|
||||
(uint8_t*)strdup(kernel_cmdline),
|
||||
strlen(kernel_cmdline)+1);
|
||||
|
||||
if (protocol >= 0x202) {
|
||||
stl_p(header+0x228, cmdline_addr);
|
||||
|
|
@ -937,7 +857,13 @@ static void load_linux(void *fw_cfg,
|
|||
|
||||
initrd_size = get_image_size(initrd_filename);
|
||||
initrd_addr = (initrd_max-initrd_size) & ~4095;
|
||||
rom_add_file_fixed(initrd_filename, initrd_addr);
|
||||
|
||||
initrd_data = qemu_malloc(initrd_size);
|
||||
load_image(initrd_filename, initrd_data);
|
||||
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, initrd_addr);
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, initrd_size);
|
||||
fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, initrd_data, initrd_size);
|
||||
|
||||
stl_p(header+0x218, initrd_addr);
|
||||
stl_p(header+0x21c, initrd_size);
|
||||
|
|
@ -957,21 +883,17 @@ static void load_linux(void *fw_cfg,
|
|||
fread(kernel, 1, kernel_size, f);
|
||||
fclose(f);
|
||||
memcpy(setup, header, MIN(sizeof(header), setup_size));
|
||||
rom_add_blob_fixed("linux-setup", setup,
|
||||
setup_size, real_addr);
|
||||
rom_add_blob_fixed(kernel_filename, kernel,
|
||||
kernel_size, prot_addr);
|
||||
qemu_free(setup);
|
||||
qemu_free(kernel);
|
||||
|
||||
/* generate bootsector to set up the initial register state */
|
||||
real_seg = real_addr >> 4;
|
||||
seg[0] = seg[2] = seg[3] = seg[4] = seg[4] = real_seg;
|
||||
seg[1] = real_seg+0x20; /* CS */
|
||||
memset(gpr, 0, sizeof gpr);
|
||||
gpr[4] = cmdline_addr-real_addr-16; /* SP (-16 is paranoia) */
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, kernel_size);
|
||||
fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size);
|
||||
|
||||
generate_bootsect(gpr, seg, 0);
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_ADDR, real_addr);
|
||||
fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size);
|
||||
fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size);
|
||||
|
||||
option_rom[nb_option_roms] = "linuxboot.bin";
|
||||
nb_option_roms++;
|
||||
}
|
||||
|
||||
static const int ide_iobase[2] = { 0x1f0, 0x170 };
|
||||
|
|
|
|||
Binary file not shown.
|
|
@ -13,7 +13,7 @@ CFLAGS += -I$(SRC_PATH)
|
|||
CFLAGS += $(call cc-option, $(CFLAGS), -fno-stack-protector)
|
||||
QEMU_CFLAGS = $(CFLAGS)
|
||||
|
||||
build-all: multiboot.bin
|
||||
build-all: multiboot.bin linuxboot.bin
|
||||
|
||||
%.img: %.o
|
||||
$(call quiet-command,$(LD) -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@")
|
||||
|
|
|
|||
|
|
@ -0,0 +1,140 @@
|
|||
/*
|
||||
* Linux 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, see <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
* Copyright Novell Inc, 2009
|
||||
* Authors: Alexander Graf <agraf@suse.de>
|
||||
*
|
||||
* Based on code in hw/pc.c.
|
||||
*/
|
||||
|
||||
#include "optionrom.h"
|
||||
|
||||
BOOT_ROM_START
|
||||
|
||||
run_linuxboot:
|
||||
|
||||
cli
|
||||
cld
|
||||
|
||||
jmp copy_kernel
|
||||
boot_kernel:
|
||||
|
||||
read_fw FW_CFG_SETUP_ADDR
|
||||
|
||||
mov %eax, %ebx
|
||||
shr $4, %ebx
|
||||
|
||||
/* All segments contain real_addr */
|
||||
mov %bx, %ds
|
||||
mov %bx, %es
|
||||
mov %bx, %fs
|
||||
mov %bx, %gs
|
||||
mov %bx, %ss
|
||||
|
||||
/* CX = CS we want to jump to */
|
||||
add $0x20, %bx
|
||||
mov %bx, %cx
|
||||
|
||||
/* SP = cmdline_addr-real_addr-16 */
|
||||
read_fw FW_CFG_CMDLINE_ADDR
|
||||
mov %eax, %ebx
|
||||
read_fw FW_CFG_SETUP_ADDR
|
||||
sub %eax, %ebx
|
||||
sub $16, %ebx
|
||||
mov %ebx, %esp
|
||||
|
||||
/* Build indirect lret descriptor */
|
||||
pushw %cx /* CS */
|
||||
xor %ax, %ax
|
||||
pushw %ax /* IP = 0 */
|
||||
|
||||
/* Clear registers */
|
||||
xor %eax, %eax
|
||||
xor %ebx, %ebx
|
||||
xor %ecx, %ecx
|
||||
xor %edx, %edx
|
||||
xor %edi, %edi
|
||||
xor %ebp, %ebp
|
||||
|
||||
/* Jump to Linux */
|
||||
lret
|
||||
|
||||
|
||||
copy_kernel:
|
||||
|
||||
/* We need to load the kernel into memory we can't access in 16 bit
|
||||
mode, so let's get into 32 bit mode, write the kernel and jump
|
||||
back again. */
|
||||
|
||||
/* Set DS to SS+SP - 0x10, so we can write our GDT descriptor there */
|
||||
mov %ss, %eax
|
||||
shl $4, %eax
|
||||
add %esp, %eax
|
||||
sub $0x10, %eax
|
||||
shr $4, %eax
|
||||
|
||||
/* Now create the GDT descriptor */
|
||||
mov %cs, %eax
|
||||
shl $4, %eax
|
||||
movw $((3 * 8) - 1), %bx
|
||||
movw %bx, %gs:0
|
||||
movl $gdt, %ebx
|
||||
add %eax, %ebx
|
||||
movl %ebx, %gs:2
|
||||
|
||||
/* And load the GDT */
|
||||
data32 lgdt %gs:0
|
||||
|
||||
/* Get us to protected mode now */
|
||||
mov $1, %eax
|
||||
mov %eax, %cr0
|
||||
|
||||
/* So we can set DS to a 32-bit segment */
|
||||
mov $0x10, %eax
|
||||
mov %eax, %ds
|
||||
|
||||
/* We're now running in 16-bit CS, but 32-bit DS! */
|
||||
|
||||
/* Load kernel and initrd */
|
||||
read_fw_blob(FW_CFG_KERNEL)
|
||||
read_fw_blob(FW_CFG_INITRD)
|
||||
read_fw_blob(FW_CFG_CMDLINE)
|
||||
read_fw_blob(FW_CFG_SETUP)
|
||||
|
||||
/* And now jump into Linux! */
|
||||
mov $0, %eax
|
||||
mov %eax, %cr0
|
||||
|
||||
/* DS = CS */
|
||||
mov %cs, %ax
|
||||
mov %ax, %ds
|
||||
|
||||
jmp boot_kernel
|
||||
|
||||
/* Variables */
|
||||
|
||||
.align 4, 0
|
||||
gdt:
|
||||
/* 0x00 */
|
||||
.byte 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
|
||||
|
||||
/* 0x08: code segment (base=0, limit=0xfffff, type=32bit code exec/read, DPL=0, 4k) */
|
||||
.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x9a, 0xcf, 0x00
|
||||
|
||||
/* 0x10: data segment (base=0, limit=0xfffff, type=32bit data read/write, DPL=0, 4k) */
|
||||
.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x92, 0xcf, 0x00
|
||||
|
||||
BOOT_ROM_END
|
||||
Loading…
Reference in New Issue