From 55c6d5467ec99653d08c01ede8412cfe7ea0d4e7 Mon Sep 17 00:00:00 2001 From: Liming Gao Date: Tue, 14 Jun 2016 16:26:46 +0800 Subject: UefiCpuPkg PiSmmCpuDxeSmm: Update Ia32/MpFuncs.nasm Use 16bit assembly code to replace hard code db. In V2: Add 0x67 prefix to far jump When we enter protected mode, with the far jump still in big real mode, the JMP instruction not only needs the 0x66 prefix (for 32-bit operand size), but also the 0x67 prefix (for 32-bit address size). Use the a32 nasm modifier to enforce this. This bug breaks S3 resume in the Ia32 + SMM_REQUIRE build of OVMF. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Liming Gao Signed-off-by: Laszlo Ersek --- UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/MpFuncs.nasm | 47 +++++++++++++---------------- 1 file changed, 21 insertions(+), 26 deletions(-) (limited to 'UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/MpFuncs.nasm') diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/MpFuncs.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/MpFuncs.nasm index fceaaf2689..f7cdcce9a7 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/MpFuncs.nasm +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/MpFuncs.nasm @@ -42,49 +42,44 @@ extern ASM_PFX(InitializeFloatingPointUnits) ;------------------------------------------------------------------------------------- ;RendezvousFunnelProc (&WakeUpBuffer,MemAddress); +BITS 16 global ASM_PFX(RendezvousFunnelProc) ASM_PFX(RendezvousFunnelProc): RendezvousFunnelProcStart: ; At this point CS = 0x(vv00) and ip= 0x0. - db 0x8c, 0xc8 ; mov ax, cs - db 0x8e, 0xd8 ; mov ds, ax - db 0x8e, 0xc0 ; mov es, ax - db 0x8e, 0xd0 ; mov ss, ax - db 0x33, 0xc0 ; xor ax, ax - db 0x8e, 0xe0 ; mov fs, ax - db 0x8e, 0xe8 ; mov gs, ax + mov ax, cs + mov ds, ax + mov es, ax + mov ss, ax + xor ax, ax + mov fs, ax + mov gs, ax flat32Start: - db 0xBE - dw BufferStart ; mov si, BufferStart - db 0x66, 0x8B, 0x14 ; mov edx,dword ptr [si] ; EDX is keeping the start address of wakeup buffer + mov si, BufferStart + mov edx,dword [si] ; EDX is keeping the start address of wakeup buffer - db 0xBE - dw GdtrProfile ; mov si, GdtrProfile - db 0x66 ; db 66h - db 0x2E, 0xF, 0x1, 0x14 ; lgdt fword ptr cs:[si] + mov si, GdtrProfile +o32 lgdt [cs:si] - db 0xBE - dw IdtrProfile ; mov si, IdtrProfile - db 0x66 ; db 66h - db 0x2E, 0xF, 0x1, 0x1C ; lidt fword ptr cs:[si] + mov si, IdtrProfile +o32 lidt [cs:si] - db 0x33, 0xC0 ; xor ax, ax - db 0x8E, 0xD8 ; mov ds, ax + xor ax, ax + mov ds, ax - db 0xF, 0x20, 0xC0 ; mov eax, cr0 ; Get control register 0 - db 0x66, 0x83, 0xC8, 0x1 ; or eax, 000000001h ; Set PE bit (bit #0) - db 0xF, 0x22, 0xC0 ; mov cr0, eax + mov eax, cr0 ; Get control register 0 + or eax, 0x000000001 ; Set PE bit (bit #0) + mov cr0, eax FLAT32_JUMP: - db 0x66, 0x67, 0xEA ; far jump - dd 0x0 ; 32-bit offset - dw 0x20 ; 16-bit selector +a32 jmp dword 0x20:0x0 +BITS 32 PMODE_ENTRY: ; protected mode entry point mov ax, 0x8 -- cgit v1.2.3