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-rw-r--r--pc-bios/linuxboot.binbin1024 -> 1024 bytes
-rw-r--r--pc-bios/optionrom/linuxboot.S37
2 files changed, 27 insertions, 10 deletions
diff --git a/pc-bios/linuxboot.bin b/pc-bios/linuxboot.bin
index 130103f..923d179 100644
--- a/pc-bios/linuxboot.bin
+++ b/pc-bios/linuxboot.bin
Binary files differ
diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S
index 5bc0af0..ba821ab 100644
--- a/pc-bios/optionrom/linuxboot.S
+++ b/pc-bios/optionrom/linuxboot.S
@@ -76,7 +76,31 @@ boot_kernel:
copy_kernel:
- /* Compute initrd address */
+ /* Read info block in low memory (0x10000 or 0x90000) */
+ read_fw FW_CFG_SETUP_ADDR
+ shr $4, %eax
+ mov %eax, %es
+ xor %edi, %edi
+ read_fw_blob_addr32_edi(FW_CFG_SETUP)
+
+ cmpw $0x203, %es:0x206 // if protocol >= 0x203
+ jae 1f // have initrd_max
+ movl $0x37ffffff, %es:0x22c // else assume 0x37ffffff
+1:
+
+ /* Check if using kernel-specified initrd address */
+ read_fw FW_CFG_INITRD_ADDR
+ mov %eax, %edi // (load_kernel wants it in %edi)
+ read_fw FW_CFG_INITRD_SIZE // find end of initrd
+ add %edi, %eax
+ xor %es:0x22c, %eax // if it matches es:0x22c
+ and $-4096, %eax // (apart from padding for page)
+ jz load_kernel // then initrd is not at top
+ // of memory
+
+ /* pc.c placed the initrd at end of memory. Compute a better
+ * initrd address based on e801 data.
+ */
mov $0xe801, %ax
xor %cx, %cx
xor %dx, %dx
@@ -107,7 +131,9 @@ copy_kernel:
read_fw FW_CFG_INITRD_SIZE
subl %eax, %edi
andl $-4096, %edi /* EDI = start of initrd */
+ movl %edi, %es:0x218 /* put it in the header */
+load_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. */
@@ -139,19 +165,10 @@ 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_CMDLINE)
- 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
mov %eax, %cr0
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