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-rw-r--r--hw/fw_cfg.h5
-rw-r--r--hw/pc.c43
-rw-r--r--pc-bios/optionrom/multiboot.S77
3 files changed, 94 insertions, 31 deletions
diff --git a/hw/fw_cfg.h b/hw/fw_cfg.h
index 359d45afe9..1e004b7070 100644
--- a/hw/fw_cfg.h
+++ b/hw/fw_cfg.h
@@ -17,7 +17,10 @@
#define FW_CFG_NUMA 0x0d
#define FW_CFG_BOOT_MENU 0x0e
#define FW_CFG_MAX_CPUS 0x0f
-#define FW_CFG_MAX_ENTRY 0x10
+#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_WRITE_CHANNEL 0x4000
#define FW_CFG_ARCH_LOCAL 0x8000
diff --git a/hw/pc.c b/hw/pc.c
index bf4718e682..55bd1a48b2 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -603,6 +603,8 @@ static int load_multiboot(void *fw_cfg,
uint32_t mb_mod_end;
uint8_t bootinfo[0x500];
uint32_t cmdline = 0x200;
+ uint8_t *mb_kernel_data;
+ uint8_t *mb_bootinfo_data;
/* Ok, let's see if it is a multiboot image.
The header is 12x32bit long, so the latest entry may be 8192 - 48. */
@@ -643,6 +645,12 @@ static int load_multiboot(void *fw_cfg,
mh_load_addr = mh_entry_addr = elf_entry;
mb_kernel_size = kernel_size;
+ mb_kernel_data = qemu_malloc(mb_kernel_size);
+ if (rom_copy(mb_kernel_data, elf_entry, kernel_size) != kernel_size) {
+ fprintf(stderr, "Error while fetching elf kernel from rom\n");
+ exit(1);
+ }
+
#ifdef DEBUG_MULTIBOOT
fprintf(stderr, "qemu: loading multiboot-elf kernel (%#x bytes) with entry %#zx\n",
mb_kernel_size, (size_t)mh_entry_addr);
@@ -656,7 +664,6 @@ static int load_multiboot(void *fw_cfg,
uint32_t mh_bss_end_addr = ldl_p(header+i+24);
#endif
uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
- uint8_t *kernel;
mh_entry_addr = ldl_p(header+i+28);
mb_kernel_size = get_file_size(f) - mb_kernel_text_offset;
@@ -676,12 +683,9 @@ static int load_multiboot(void *fw_cfg,
mb_kernel_size, mh_load_addr);
#endif
- kernel = qemu_malloc(mb_kernel_size);
+ mb_kernel_data = qemu_malloc(mb_kernel_size);
fseek(f, mb_kernel_text_offset, SEEK_SET);
- fread(kernel, 1, mb_kernel_size, f);
- rom_add_blob_fixed(kernel_filename, kernel, mb_kernel_size,
- mh_load_addr);
- qemu_free(kernel);
+ fread(mb_kernel_data, 1, mb_kernel_size, f);
fclose(f);
}
@@ -732,9 +736,14 @@ static int load_multiboot(void *fw_cfg,
exit(1);
}
mb_mod_end = mb_mod_start + mb_mod_length;
- rom_add_file_fixed(initrd_filename, mb_mod_start);
-
mb_mod_count++;
+
+ /* append module data at the end of last module */
+ mb_kernel_data = qemu_realloc(mb_kernel_data,
+ mh_load_addr - mb_mod_end);
+ load_image(initrd_filename,
+ mb_kernel_data + mb_mod_start - mh_load_addr);
+
stl_p(bootinfo + mb_mod_info + 0, mb_mod_start);
stl_p(bootinfo + mb_mod_info + 4, mb_mod_start + mb_mod_length);
stl_p(bootinfo + mb_mod_info + 12, 0x0); /* reserved */
@@ -774,13 +783,21 @@ static int load_multiboot(void *fw_cfg,
fprintf(stderr, "multiboot: mh_entry_addr = %#x\n", mh_entry_addr);
#endif
+ /* save bootinfo off the stack */
+ mb_bootinfo_data = qemu_malloc(sizeof(bootinfo));
+ memcpy(mb_bootinfo_data, bootinfo, sizeof(bootinfo));
+
/* Pass variables to option rom */
- fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_entry_addr);
- fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, mb_bootinfo);
- fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, mmap_addr);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mb_mod_end - mh_load_addr);
+ fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, mb_kernel_data,
+ mb_mod_end - mh_load_addr);
- rom_add_blob_fixed("multiboot-info", bootinfo, sizeof(bootinfo),
- mb_bootinfo);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, mb_bootinfo);
+ fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
+ fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
+ sizeof(bootinfo));
option_rom[nb_option_roms] = "multiboot.bin";
nb_option_roms++;
diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
index e6cbefdc92..dafac7392e 100644
--- a/pc-bios/optionrom/multiboot.S
+++ b/pc-bios/optionrom/multiboot.S
@@ -26,6 +26,14 @@
#define MULTIBOOT_MAGIC 0x2badb002
+#define GS_PROT_JUMP 0
+#define GS_GDT_DESC 6
+
+/* 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 */
@@ -44,12 +52,31 @@
bswap %eax
.endm
+/*
+ * 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 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; \
+ DEBUG_HERE \
+ rep insb (%dx), %es:(%edi);
+
.code16
.text
.global _start
_start:
.short 0xaa55
- .byte 1 /* (_end - _start) / 512 */
+ .byte (_end - _start) / 512
push %eax
push %ds
@@ -57,10 +84,6 @@ _start:
xor %ax, %ax
mov %ax, %ds
- /* save old int 19 */
- mov (0x19*4), %eax
- mov %eax, %cs:old_int19
-
/* install our int 19 handler */
movw $int19_handler, (0x19*4)
mov %cs, (0x19*4+2)
@@ -84,15 +107,34 @@ run_multiboot:
mov %cs, %eax
shl $0x4, %eax
- /* fix the gdt descriptor to be PC relative */
- mov (gdt_desc+2), %ebx
- add %eax, %ebx
- mov %ebx, (gdt_desc+2)
+ /* set up a long jump descriptor that is PC relative */
- /* fix the prot mode indirect jump to be PC relative */
+ /* move stack memory to %gs */
+ mov %ss, %ecx
+ shl $0x4, %ecx
+ mov %esp, %ebx
+ add %ebx, %ecx
+ sub $0x20, %ecx
+ sub $0x30, %esp
+ shr $0x4, %ecx
+ mov %cx, %gs
+
+ /* now push the indirect jump decriptor there */
mov (prot_jump), %ebx
add %eax, %ebx
- mov %ebx, (prot_jump)
+ movl %ebx, %gs:GS_PROT_JUMP
+ mov $8, %bx
+ movw %bx, %gs:GS_PROT_JUMP + 4
+
+ /* fix the gdt descriptor to be PC relative */
+ movw (gdt_desc), %bx
+ movw %bx, %gs:GS_GDT_DESC
+ movl (gdt_desc+2), %ebx
+ add %eax, %ebx
+ movl %ebx, %gs:GS_GDT_DESC + 2
+
+ /* Read the bootinfo struct into RAM */
+ read_fw_blob(FW_CFG_INITRD)
/* FS = bootinfo_struct */
read_fw FW_CFG_INITRD_ADDR
@@ -100,7 +142,7 @@ run_multiboot:
mov %ax, %fs
/* ES = mmap_addr */
- read_fw FW_CFG_INITRD_SIZE
+ mov %eax, %fs:0x48
shr $4, %eax
mov %ax, %es
@@ -144,7 +186,7 @@ mmap_done:
real_to_prot:
/* Load the GDT before going into protected mode */
lgdt:
- data32 lgdt %cs:gdt_desc
+ data32 lgdt %gs:GS_GDT_DESC
/* get us to protected mode now */
movl $1, %eax
@@ -152,7 +194,7 @@ lgdt:
/* the LJMP sets CS for us and gets us to 32-bit */
ljmp:
- data32 ljmp *%cs:prot_jump
+ data32 ljmp *%gs:GS_PROT_JUMP
prot_mode:
.code32
@@ -165,8 +207,11 @@ prot_mode:
movl %eax, %fs
movl %eax, %gs
+ /* Read the kernel and modules into RAM */
+ read_fw_blob(FW_CFG_KERNEL)
+
/* Jump off to the kernel */
- read_fw FW_CFG_KERNEL_ADDR
+ read_fw FW_CFG_KERNEL_ENTRY
mov %eax, %ecx
/* EBX contains a pointer to the bootinfo struct */
@@ -180,8 +225,6 @@ ljmp2:
/* Variables */
.align 4, 0
-old_int19: .long 0
-
prot_jump: .long prot_mode
.short 8
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-30 14:09:48 +0000