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Convert linux bootrom to external rom and fw_cfg

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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 2009-11-12 21:53:14 +01:00 • committed by Anthony Liguori
parent dd4b2659cd
commit 57a46d0579
5 changed files with 170 additions and 102 deletions
Download patch file Download diff file Expand all files Collapse all files

8
hw/fw_cfg.h
View file

@ -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
View file

@ -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 };