diff options
Diffstat (limited to 'pc-bios/optionrom/linuxboot.S')
| -rw-r--r-- | pc-bios/optionrom/linuxboot.S | 47 |
1 files changed, 43 insertions, 4 deletions
diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S index 748c831160..5bc0af08e0 100644 --- a/pc-bios/optionrom/linuxboot.S +++ b/pc-bios/optionrom/linuxboot.S @@ -76,14 +76,45 @@ boot_kernel: copy_kernel: + /* Compute initrd address */ + mov $0xe801, %ax + xor %cx, %cx + xor %dx, %dx + int $0x15 + + /* Output could be in AX/BX or CX/DX */ + or %cx, %cx + jnz 1f + or %dx, %dx + jnz 1f + mov %ax, %cx + mov %bx, %dx +1: + + or %dx, %dx + jnz 2f + addw $1024, %cx /* add 1 MB */ + movzwl %cx, %edi + shll $10, %edi /* convert to bytes */ + jmp 3f + +2: + addw $16777216 >> 16, %dx /* add 16 MB */ + movzwl %dx, %edi + shll $16, %edi /* convert to bytes */ + +3: + read_fw FW_CFG_INITRD_SIZE + subl %eax, %edi + andl $-4096, %edi /* EDI = start of initrd */ /* 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. */ /* Reserve space on the stack for our GDT descriptor. */ - mov %esp, %ebp - sub $16, %esp + mov %esp, %ebp + sub $16, %esp /* Now create the GDT descriptor */ movw $((3 * 8) - 1), -16(%bp) @@ -108,10 +139,18 @@ copy_kernel: /* We're now running in 16-bit CS, but 32-bit ES! */ /* Load kernel and initrd */ + pushl %edi + read_fw_blob_addr32_edi(FW_CFG_INITRD) read_fw_blob_addr32(FW_CFG_KERNEL) - read_fw_blob_addr32(FW_CFG_INITRD) read_fw_blob_addr32(FW_CFG_CMDLINE) - read_fw_blob_addr32(FW_CFG_SETUP) + + read_fw FW_CFG_SETUP_ADDR + mov %eax, %edi + mov %eax, %ebx + read_fw_blob_addr32_edi(FW_CFG_SETUP) + + /* Update the header with the initrd address we chose above */ + popl %es:0x218(%ebx) /* And now jump into Linux! */ mov $0, %eax |