Dear Trammell,
Welcome to coreboot. Am Mittwoch, den 10.08.2016, 07:03 -0600 schrieb Trammell Hudson: > 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 I have no idea, but could it be related to KASRL (Kernel Address Space Layout Randomization)? Thanks, Paul PS: Please note, that officially coreboot is spelled all lowercase (see your email subject). (Depending on your localization(?) you might want to start it with a capital letter, but please never CamelCase.)
signature.asc
Description: This is a digitally signed message part
-- coreboot mailing list: coreboot@coreboot.org https://www.coreboot.org/mailman/listinfo/coreboot
