Hi Simon, On Mon, Jul 6, 2015 at 4:31 PM, Bin Meng <[email protected]> wrote: > From: Jian Luo <[email protected]> > > PCI option rom may use different SS during its execution, so it is not > safe to assume esp pointed to the same location in the protected mode. > > Signed-off-by: Jian Luo <[email protected]> > Signed-off-by: Bin Meng <[email protected]> > > --- > > Changes in v2: > - Add comments for the changes in the assembly codes > > arch/x86/lib/bios_asm.S | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/arch/x86/lib/bios_asm.S b/arch/x86/lib/bios_asm.S > index 4faa70e..e559228 100644 > --- a/arch/x86/lib/bios_asm.S > +++ b/arch/x86/lib/bios_asm.S > @@ -246,6 +246,9 @@ __interrupt_handler_16bit = PTR_TO_REAL_MODE(.) > push %fs > push %gs > > + /* Save real mode SS */ > + movw %ss, %cs:__realmode_ss > + > /* Clear DF to not break ABI assumptions */ > cld > > @@ -258,12 +261,29 @@ __interrupt_handler_16bit = PTR_TO_REAL_MODE(.) > > enter_protected_mode > > + /* > + * Now we are in protect mode. We need compute the right ESP based on > + * saved real mode SS otherwise interrupt_handler() won't get correct > + * parameters from the stack. > + */ > + movzwl %cs:__realmode_ss, %ecx > + shll $4, %ecx > + addl %ecx, %esp > + > /* Call the C interrupt handler */ > movl $interrupt_handler, %eax > call *%eax > > + /* Restore read mode ESP based on saved SS */ > + movzwl %cs:__realmode_ss, %ecx > + shll $4, %ecx > + subl %ecx, %esp > + > enter_real_mode > > + /* Restore real mode SS */ > + movw %cs:__realmode_ss, %ss > + > /* > * Restore all registers, including those manipulated by the C > * handler > @@ -276,6 +296,9 @@ __interrupt_handler_16bit = PTR_TO_REAL_MODE(.) > popal > iret > > +__realmode_ss = PTR_TO_REAL_MODE(.) > + .word 0 > + > .globl asm_realmode_code_size > asm_realmode_code_size: > .long . - asm_realmode_code > --
Sorry I have to respin this patch. Please check the new one here: http://patchwork.ozlabs.org/patch/491496/ Regards, Bin _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
