ArmPkg/Drivers/CpuDxe/AArch64/ExceptionSupport.S
//
// Copyright (c) 2011 - 2013 ARM LTD. All rights reserved.<BR>
//
// This program and the accompanying materials
// are licensed and made available under the terms and conditions of the BSD License
// which accompanies this distribution. The full text of the license may be found at
// http://opensource.org/licenses/bsd-license.php
//
// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
//
//------------------------------------------------------------------------------
#include <Library/PcdLib.h>
#include <AsmMacroIoLibV8.h>
/*
This is the stack constructed by the exception handler (low address to high address).
X0 to FAR makes up the EFI_SYSTEM_CONTEXT for AArch64.
UINT64 X0; 0x000
UINT64 X1; 0x008
UINT64 X2; 0x010
UINT64 X3; 0x018
UINT64 X4; 0x020
UINT64 X5; 0x028
UINT64 X6; 0x030
UINT64 X7; 0x038
UINT64 X8; 0x040
UINT64 X9; 0x048
UINT64 X10; 0x050
UINT64 X11; 0x058
UINT64 X12; 0x060
UINT64 X13; 0x068
UINT64 X14; 0x070
UINT64 X15; 0x078
UINT64 X16; 0x080
UINT64 X17; 0x088
UINT64 X18; 0x090
UINT64 X19; 0x098
UINT64 X20; 0x0a0
UINT64 X21; 0x0a8
UINT64 X22; 0x0b0
UINT64 X23; 0x0b8
UINT64 X24; 0x0c0
UINT64 X25; 0x0c8
UINT64 X26; 0x0d0
UINT64 X27; 0x0d8
UINT64 X28; 0x0e0
UINT64 FP; 0x0e8 // x29 - Frame Pointer
UINT64 LR; 0x0f0 // x30 - Link Register
UINT64 SP; 0x0f8 // x31 - Stack Pointer
// FP/SIMD Registers. 128bit if used as Q-regs.
UINT64 V0[2]; 0x100
UINT64 V1[2]; 0x110
UINT64 V2[2]; 0x120
UINT64 V3[2]; 0x130
UINT64 V4[2]; 0x140
UINT64 V5[2]; 0x150
UINT64 V6[2]; 0x160
UINT64 V7[2]; 0x170
UINT64 V8[2]; 0x180
UINT64 V9[2]; 0x190
UINT64 V10[2]; 0x1a0
UINT64 V11[2]; 0x1b0
UINT64 V12[2]; 0x1c0
UINT64 V13[2]; 0x1d0
UINT64 V14[2]; 0x1e0
UINT64 V15[2]; 0x1f0
UINT64 V16[2]; 0x200
UINT64 V17[2]; 0x210
UINT64 V18[2]; 0x220
UINT64 V19[2]; 0x230
UINT64 V20[2]; 0x240
UINT64 V21[2]; 0x250
UINT64 V22[2]; 0x260
UINT64 V23[2]; 0x270
UINT64 V24[2]; 0x280
UINT64 V25[2]; 0x290
UINT64 V26[2]; 0x2a0
UINT64 V27[2]; 0x2b0
UINT64 V28[2]; 0x2c0
UINT64 V29[2]; 0x2d0
UINT64 V30[2]; 0x2e0
UINT64 V31[2]; 0x2f0
// System Context
UINT64 ELR; 0x300 // Exception Link Register
UINT64 SPSR; 0x308 // Saved Processor Status Register
UINT64 FPSR; 0x310 // Floating Point Status Register
UINT64 ESR; 0x318 // EL1 Fault Address Register
UINT64 FAR; 0x320 // EL1 Exception syndrome register
UINT64 Padding;0x328 // Required for stack alignment
*/
ASM_GLOBAL ASM_PFX(ExceptionHandlersStart)
ASM_GLOBAL ASM_PFX(ExceptionHandlersEnd)
ASM_GLOBAL ASM_PFX(CommonExceptionEntry)
ASM_GLOBAL ASM_PFX(AsmCommonExceptionEntry)
ASM_GLOBAL ASM_PFX(CommonCExceptionHandler)
.text
.align 11
#define GP_CONTEXT_SIZE (32 * 8)
#define FP_CONTEXT_SIZE (32 * 16)
#define SYS_CONTEXT_SIZE ( 6 * 8) // 5 SYS regs + Alignment requirement (ie: the stack must be aligned on 0x10)
// Cannot str x31 directly
#define ALL_GP_REGS \
REG_PAIR (x0, x1, 0x000, GP_CONTEXT_SIZE); \
REG_PAIR (x2, x3, 0x010, GP_CONTEXT_SIZE); \
REG_PAIR (x4, x5, 0x020, GP_CONTEXT_SIZE); \
REG_PAIR (x6, x7, 0x030, GP_CONTEXT_SIZE); \
REG_PAIR (x8, x9, 0x040, GP_CONTEXT_SIZE); \
REG_PAIR (x10, x11, 0x050, GP_CONTEXT_SIZE); \
REG_PAIR (x12, x13, 0x060, GP_CONTEXT_SIZE); \
REG_PAIR (x14, x15, 0x070, GP_CONTEXT_SIZE); \
REG_PAIR (x16, x17, 0x080, GP_CONTEXT_SIZE); \
REG_PAIR (x18, x19, 0x090, GP_CONTEXT_SIZE); \
REG_PAIR (x20, x21, 0x0a0, GP_CONTEXT_SIZE); \
REG_PAIR (x22, x23, 0x0b0, GP_CONTEXT_SIZE); \
REG_PAIR (x24, x25, 0x0c0, GP_CONTEXT_SIZE); \
REG_PAIR (x26, x27, 0x0d0, GP_CONTEXT_SIZE); \
REG_PAIR (x28, x29, 0x0e0, GP_CONTEXT_SIZE); \
REG_ONE (x30, 0x0f0, GP_CONTEXT_SIZE);
// In order to save the SP we need to put it somwhere else first.
// STR only works with XZR/WZR directly
#define SAVE_SP \
add x1, sp, FP_CONTEXT_SIZE + SYS_CONTEXT_SIZE; \
REG_ONE (x1, 0x0f8, GP_CONTEXT_SIZE);
#define ALL_FP_REGS \
REG_PAIR (q0, q1, 0x000, FP_CONTEXT_SIZE); \
REG_PAIR (q2, q3, 0x020, FP_CONTEXT_SIZE); \
REG_PAIR (q4, q5, 0x040, FP_CONTEXT_SIZE); \
REG_PAIR (q6, q7, 0x060, FP_CONTEXT_SIZE); \
REG_PAIR (q8, q9, 0x080, FP_CONTEXT_SIZE); \
REG_PAIR (q10, q11, 0x0a0, FP_CONTEXT_SIZE); \
REG_PAIR (q12, q13, 0x0c0, FP_CONTEXT_SIZE); \
REG_PAIR (q14, q15, 0x0e0, FP_CONTEXT_SIZE); \
REG_PAIR (q16, q17, 0x100, FP_CONTEXT_SIZE); \
REG_PAIR (q18, q19, 0x120, FP_CONTEXT_SIZE); \
REG_PAIR (q20, q21, 0x140, FP_CONTEXT_SIZE); \
REG_PAIR (q22, q23, 0x160, FP_CONTEXT_SIZE); \
REG_PAIR (q24, q25, 0x180, FP_CONTEXT_SIZE); \
REG_PAIR (q26, q27, 0x1a0, FP_CONTEXT_SIZE); \
REG_PAIR (q28, q29, 0x1c0, FP_CONTEXT_SIZE); \
REG_PAIR (q30, q31, 0x1e0, FP_CONTEXT_SIZE);
#define ALL_SYS_REGS \
REG_PAIR (x1, x2, 0x000, SYS_CONTEXT_SIZE); \
REG_PAIR (x3, x4, 0x010, SYS_CONTEXT_SIZE); \
REG_ONE (x5, 0x020, SYS_CONTEXT_SIZE);
//
// This code gets copied to the ARM vector table
// VectorTableStart - VectorTableEnd gets copied
//
ASM_PFX(ExceptionHandlersStart):
//
// Current EL with SP0 : 0x0 - 0x180
//
.align 7
ASM_PFX(SynchronousExceptionSP0):
b ASM_PFX(SynchronousExceptionEntry)
.align 7
ASM_PFX(IrqSP0):
b ASM_PFX(IrqEntry)
.align 7
ASM_PFX(FiqSP0):
b ASM_PFX(FiqEntry)
.align 7
ASM_PFX(SErrorSP0):
b ASM_PFX(SErrorEntry)
//
// Current EL with SPx: 0x200 - 0x380
//
.align 7
ASM_PFX(SynchronousExceptionSPx):
b ASM_PFX(SynchronousExceptionEntry)
.align 7
ASM_PFX(IrqSPx):
b ASM_PFX(IrqEntry)
.align 7
ASM_PFX(FiqSPx):
b ASM_PFX(FiqEntry)
.align 7
ASM_PFX(SErrorSPx):
b ASM_PFX(SErrorEntry)
//
// Lower EL using AArch64 : 0x400 - 0x580
//
.align 7
ASM_PFX(SynchronousExceptionA64):
b ASM_PFX(SynchronousExceptionEntry)
.align 7
ASM_PFX(IrqA64):
b ASM_PFX(IrqEntry)
.align 7
ASM_PFX(FiqA64):
b ASM_PFX(FiqEntry)
.align 7
ASM_PFX(SErrorA64):
b ASM_PFX(SErrorEntry)
//
// Lower EL using AArch32 : 0x0 - 0x180
//
.align 7
ASM_PFX(SynchronousExceptionA32):
b ASM_PFX(SynchronousExceptionEntry)
.align 7
ASM_PFX(IrqA32):
b ASM_PFX(IrqEntry)
.align 7
ASM_PFX(FiqA32):
b ASM_PFX(FiqEntry)
.align 7
ASM_PFX(SErrorA32):
b ASM_PFX(SErrorEntry)
#undef REG_PAIR
#undef REG_ONE
#define REG_PAIR(REG1, REG2, OFFSET, CONTEXT_SIZE) stp REG1, REG2, [sp, #(OFFSET-CONTEXT_SIZE)]
#define REG_ONE(REG1, OFFSET, CONTEXT_SIZE) str REG1, [sp, #(OFFSET-CONTEXT_SIZE)]
ASM_PFX(SynchronousExceptionEntry):
// Move the stackpointer so we can reach our structure with the str instruction.
sub sp, sp, FP_CONTEXT_SIZE + SYS_CONTEXT_SIZE
// Save all the General regs before touching x0 and x1.
// This does not save r31(SP) as it is special. We do that later.
ALL_GP_REGS
// Record the tipe of exception that occured.
mov x0, #EXCEPT_AARCH64_SYNCHRONOUS_EXCEPTIONS
// Jump to our general handler to deal with all the common parts and process the exception.
ldr x1, ASM_PFX(CommonExceptionEntry)
br x1
ASM_PFX(IrqEntry):
sub sp, sp, FP_CONTEXT_SIZE + SYS_CONTEXT_SIZE
ALL_GP_REGS
mov x0, #EXCEPT_AARCH64_IRQ
ldr x1, ASM_PFX(CommonExceptionEntry)
br x1
ASM_PFX(FiqEntry):
sub sp, sp, FP_CONTEXT_SIZE + SYS_CONTEXT_SIZE
ALL_GP_REGS
mov x0, #EXCEPT_AARCH64_FIQ
ldr x1, ASM_PFX(CommonExceptionEntry)
br x1
ASM_PFX(SErrorEntry):
sub sp, sp, FP_CONTEXT_SIZE + SYS_CONTEXT_SIZE
ALL_GP_REGS
mov x0, #EXCEPT_AARCH64_SERROR
ldr x1, ASM_PFX(CommonExceptionEntry)
br x1
//
// This gets patched by the C code that patches in the vector table
//
.align 3
ASM_PFX(CommonExceptionEntry):
.dword ASM_PFX(AsmCommonExceptionEntry)
ASM_PFX(ExceptionHandlersEnd):
//
// This code runs from CpuDxe driver loaded address. It is patched into
// CommonExceptionEntry.
//
ASM_PFX(AsmCommonExceptionEntry):
/* NOTE:
We have to break up the save code because the immidiate value to be used
with the SP is to big to do it all in one step so we need to shuffle the SP
along as we go. (we only have 9bits of immediate to work with) */
// Save the current Stack pointer before we start modifying it.
SAVE_SP
// Preserve the stack pointer we came in with before we modify it
EL1_OR_EL2(x1)
1:mrs x1, elr_el1 // Exception Link Register
mrs x2, spsr_el1 // Saved Processor Status Register 32bit
mrs x3, fpsr // Floating point Status Register 32bit
mrs x4, esr_el1 // EL1 Exception syndrome register 32bit
mrs x5, far_el1 // EL1 Fault Address Register
b 3f
2:mrs x1, elr_el2 // Exception Link Register
mrs x2, spsr_el2 // Saved Processor Status Register 32bit
mrs x3, fpsr // Floating point Status Register 32bit
mrs x4, esr_el2 // EL1 Exception syndrome register 32bit
mrs x5, far_el2 // EL1 Fault Address Register
// Adjust SP to save next set
3:add sp, sp, FP_CONTEXT_SIZE
// Push FP regs to Stack.
ALL_FP_REGS
// Adjust SP to save next set
add sp, sp, SYS_CONTEXT_SIZE
// Save the SYS regs
ALL_SYS_REGS
// Point to top of struct after all regs saved
sub sp, sp, GP_CONTEXT_SIZE + FP_CONTEXT_SIZE + SYS_CONTEXT_SIZE
// x0 still holds the exception type.
// Set x1 to point to the top of our struct on the Stack
mov x1, sp
// CommonCExceptionHandler (
// IN EFI_EXCEPTION_TYPE ExceptionType, R0
// IN OUT EFI_SYSTEM_CONTEXT SystemContext R1
// )
// Call the handler as defined above
// For now we spin in the handler if we received an abort of some kind.
// We do not try to recover.
bl ASM_PFX(CommonCExceptionHandler) // Call exception handler
// Defines for popping from stack
#undef REG_PAIR
#undef REG_ONE
#define REG_PAIR(REG1, REG2, OFFSET, CONTEXT_SIZE) ldp REG1, REG2, [sp, #(OFFSET-CONTEXT_SIZE)]
#define REG_ONE(REG1, OFFSET, CONTEXT_SIZE) ldr REG1, [sp, #(OFFSET-CONTEXT_SIZE)]
// pop all regs and return from exception.
add sp, sp, GP_CONTEXT_SIZE
ALL_GP_REGS
// Adjust SP to pop next set
add sp, sp, FP_CONTEXT_SIZE
// Pop FP regs to Stack.
ALL_FP_REGS
// Adjust SP to be where we started from when we came into the handler.
// The handler can not change the SP.
add sp, sp, SYS_CONTEXT_SIZE
eret
#undef REG_PAIR
#undef REG_ONE