Messages in this thread | | | Date | Sun, 23 Dec 2012 10:00:26 -0800 | Subject | Re: [PATCH v7 00/27] x86, boot, 64bit: Add support for loading ramdisk and bzImage above 4G | From | Yinghai Lu <> |
| |
On Sun, Dec 23, 2012 at 6:33 AM, H. Peter Anvin <hpa@zytor.com> wrote: > Explanation please? >
you have following change in the patch
/* Finally jump to run C code and to be on real kernel address * Since we are running on identity-mapped space we have to jump * to the full 64bit address, this is only possible as indirect * jump. In addition we need to ensure %cs is set so we make this - * a far return. + * a far jump. */ - movq initial_code(%rip),%rax pushq $0 # fake return address to stop unwinder - pushq $__KERNEL_CS # set correct cs - pushq %rax # target address in negative space - lretq + /* gas 2.22 is buggy and mis-assembles ljmpq */ + rex64 ljmp *initial_code(%rip)
#ifdef CONFIG_HOTPLUG_CPU /*
remove that change, AMD systems works again.
Yinghai
| |