The Linux 4.7 kernel payload crashes early in the boot process
with CoreBoot 4.4. I traced it to these instructions that are
finding a safe spot to decompress the rest of the kernel and
patched around it with a hard coded location:
diff -u --recursive
/home/hudson/build/clean/linux-4.7/arch/x86/boot/compressed/head_64.S
./linux-4.7/arch/x86/boot/compressed/head_64.S
--- /home/hudson/build/clean/linux-4.7/arch/x86/boot/compressed/head_64.S
2016-07-24 15:23:50.000000000 -0400
+++ ./linux-4.7/arch/x86/boot/compressed/head_64.S 2016-08-05
12:07:11.399854225 -0400
@@ -340,9 +357,15 @@
1:
/* Target address to relocate to for decompression */
+#if 0
movl BP_init_size(%rsi), %ebx
subl $_end, %ebx
addq %rbp, %rbx
+#else
+ // coreboot does not populate the init_size boot param?
+ // fake it with a hard coded value
+ movl $0x97b000, %ebx
+#endif
/* Set up the stack */
leaq boot_stack_end(%rbx), %rsp
It seems that the Linux kernel bzImage is supposed to set this value,
rather than coreboot, so my comment is likely incorrect.
Dumping linux-4.7/arch/x86/boot/header.o, it looks like init_siez
is supposed to be 0xcf5000, so I wonder if %rsi is pointing to the
wrong location.
In 4.6.4 the computed address was hardcoded:
movl $LOAD_PHYSICAL_ADDR, %ebx
/* Target address to relocate to for decompression */
addl $z_extract_offset, %ebx
3e: bb 00 00 00 01 mov $0x1000000,%ebx
43: 81 c3 00 00 00 00 add $0x0,%ebx
--
Trammell
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