On Tue, 08 Apr, at 06:46:49AM, Tetsuo Handa wrote:
> Fleming, Matt wrote:
> > On 7 April 2014 21:42, Andi Kleen <[email protected]> wrote:
> > >
> > > This sounds like the UEFI boot corrupts some memory?
> >
> > Hmpf, yeah. I'll take a look in the morning.
> >
> > Thomas, you mention you're running in a 32-bit vm earlier in this
> > thread. Any chance you're using ovmf because that would make it much
> > easier to track this down?
> >
>
> I'm not familiar with UEFI boot, but it could happen because what
> I experienced with BIOS boot was an address dependent behavior.
>
> https://lkml.org/lkml/2013/9/4/188
OK, that's a pretty good clue, thanks Tetsuo.
Thomas, could you try this patch? It seems the use of code32_start in
the EFI boot stub was totally wrong for the case where the boot stub
relocates the kernel - you're likely to hit this path if using the EFI
boot stub directly from the EFI shell or gummiboot.
It was pointing at the start of the kernel image and not the protected
mode code.
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 1e6146137f8e..65e7d7e0ef1b 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1016,6 +1016,9 @@ void setup_graphics(struct boot_params *boot_params)
* Because the x86 boot code expects to be passed a boot_params we
* need to create one ourselves (usually the bootloader would create
* one for us).
+ *
+ * The caller is responsible for filling out ->code32_start in the
+ * returned boot_params.
*/
struct boot_params *make_boot_params(struct efi_config *c)
{
@@ -1081,8 +1084,6 @@ struct boot_params *make_boot_params(struct efi_config *c)
hdr->vid_mode = 0xffff;
hdr->boot_flag = 0xAA55;
- hdr->code32_start = (__u64)(unsigned long)image->image_base;
-
hdr->type_of_loader = 0x21;
/* Convert unicode cmdline to ascii */
diff --git a/arch/x86/boot/compressed/head_32.S
b/arch/x86/boot/compressed/head_32.S
index de9d4200d305..cbed1407a5cd 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -59,6 +59,7 @@ ENTRY(efi_pe_entry)
call make_boot_params
cmpl $0, %eax
je fail
+ movl %esi, BP_code32_start(%eax)
popl %ecx
pushl %eax
pushl %ecx
@@ -90,12 +91,7 @@ fail:
hlt
jmp fail
2:
- call 3f
-3:
- popl %eax
- subl $3b, %eax
- subl BP_pref_address(%esi), %eax
- add BP_code32_start(%esi), %eax
+ movl BP_code32_start(%esi), %eax
leal preferred_addr(%eax), %eax
jmp *%eax
diff --git a/arch/x86/boot/compressed/head_64.S
b/arch/x86/boot/compressed/head_64.S
index 57e58a5fa210..0d558ee899ae 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -261,6 +261,8 @@ ENTRY(efi_pe_entry)
cmpq $0,%rax
je fail
mov %rax, %rsi
+ leaq startup_32(%rip), %rax
+ movl %eax, BP_code32_start(%rsi)
jmp 2f /* Skip the relocation */
handover_entry:
@@ -284,12 +286,7 @@ fail:
hlt
jmp fail
2:
- call 3f
-3:
- popq %rax
- subq $3b, %rax
- subq BP_pref_address(%rsi), %rax
- add BP_code32_start(%esi), %eax
+ movl BP_code32_start(%esi), %eax
leaq preferred_addr(%rax), %rax
jmp *%rax
--
Matt Fleming, Intel Open Source Technology Center
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