From 53b6a1d8973d8e067ef9561154aad789b91c936a Mon Sep 17 00:00:00 2001 From: yuhzheng Date: Fri, 31 Jan 2020 19:31:50 +0000 Subject: [PATCH] ESP GCC port -- Added LoadStore Exception handlers. https://github.com/FreeRTOS/FreeRTOS-Kernel/pull/9 -- Handles LoadStoreErrorCause and LoadStoreAlignmentCause allowing to use 32-bit memory region (IRAM) as 8-bit or 16-bit memory region git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@2816 1d2547de-c912-0410-9cb9-b8ca96c0e9e2 --- .../Xtensa_ESP32/xtensa_loadstore_handler.S | 559 ++++++++++++++++++ .../GCC/Xtensa_ESP32/xtensa_vectors.S | 28 + 2 files changed, 587 insertions(+) create mode 100644 FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_loadstore_handler.S diff --git a/FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_loadstore_handler.S b/FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_loadstore_handler.S new file mode 100644 index 000000000..f4312df79 --- /dev/null +++ b/FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_loadstore_handler.S @@ -0,0 +1,559 @@ +/* + Copyright 2019 Espressif Systems (Shanghai) PTE LTD + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + * LoadStoreErrorCause: Occurs when trying to access 32 bit addressable memory region as 8 bit or 16 bit + * LoadStoreAlignmentCause: Occurs when trying to access in an unaligned manner + * + * xxxx xxxx = imm8 field + * yyyy = imm4 field + * ssss = s field + * tttt = t field + * + * 16 0 + * ------------------- + * L32I.N yyyy ssss tttt 1000 + * S32I.N yyyy ssss tttt 1001 + * + * 23 0 + * ----------------------------- + * L8UI xxxx xxxx 0000 ssss tttt 0010 <- LoadStoreError + * L16UI xxxx xxxx 0001 ssss tttt 0010 <- LoadStoreError, LoadStoreAlignment + * L16SI xxxx xxxx 1001 ssss tttt 0010 <- LoadStoreError, LoadStoreAlignment + * L32I xxxx xxxx 0010 ssss tttt 0010 <- LoadStoreAlignment + * + * S8I xxxx xxxx 0100 ssss tttt 0010 <- LoadStoreError + * S16I xxxx xxxx 0101 ssss tttt 0010 <- LoadStoreError, LoadStoreAlignment + * S32I xxxx xxxx 0110 ssss tttt 0010 <- LoadStoreAlignment + * + * ******* UNSUPPORTED ******* + * + * L32E 0000 1001 rrrr ssss tttt 0000 + * S32E 0100 1001 rrrr ssss tttt 0000 + * ----------------------------- + */ + +#include "xtensa_rtos.h" +#include "sdkconfig.h" +#include "soc/soc.h" + +#define LOADSTORE_HANDLER_STACK_SZ 8 + .section .bss, "aw" + .balign 16 +LoadStoreHandlerStack: + .rept LOADSTORE_HANDLER_STACK_SZ + .word 0 + .endr + + +/* LoadStoreErrorCause handler: + * + * Completes 8-bit or 16-bit load/store instructions from 32-bit aligned memory region + * Called from UserExceptionVector if EXCCAUSE is LoadStoreErrorCause + */ + + .global LoadStoreErrorHandler + .section .iram1, "ax" + + .literal_position + + .balign 4 +LoadStoreErrorHandler: + .type LoadStoreErrorHandler, @function + + wsr a0, depc // Save return address in depc + mov a0, sp + movi sp, LoadStoreHandlerStack + s32i a0, sp, 0x04 // Since a0 contains value of a1 + s32i a2, sp, 0x08 + s32i a3, sp, 0x0c + s32i a4, sp, 0x10 + + rsr a0, sar // Save SAR in a0 to restore later + + /* Check whether the address lies in the valid range */ + rsr a3, excvaddr + movi a4, _iram_end // End of code section of IRAM + bge a3, a4, 1f + movi a4, SOC_CACHE_APP_LOW // Check if in APP cache region + blt a3, a4, .LS_wrong_opcode + movi a4, SOC_CACHE_APP_HIGH + bge a3, a4, .LS_wrong_opcode + j 2f + +1: + movi a4, SOC_IRAM_HIGH // End of IRAM address range + bge a3, a4, .LS_wrong_opcode + +2: + /* Examine the opcode which generated the exception */ + /* Note: Instructions are in this order to avoid pipeline stalls. */ + rsr a2, epc1 + movi a4, ~3 + ssa8l a2 // sar is now correct shift for aligned read + and a2, a2, a4 // a2 now 4-byte aligned address of instruction + l32i a4, a2, 0 + l32i a2, a2, 4 + + src a2, a2, a4 // a2 now instruction that failed + bbci a2, 1, .LS_wrong_opcode + bbsi a2, 14, .LSE_store_op // Store instruction + + /* l8/l16ui/l16si */ + movi a4, ~3 + and a4, a3, a4 // a4 now word aligned read address + + ssa8l a3 // sar is now shift to extract a3's byte + l32i a4, a4, 0 // perform the actual read + srl a4, a4 // shift right correct distance + extui a3, a2, 12, 4 + bnez a3, 1f // l16ui/l16si + extui a4, a4, 0, 8 // mask off bits needed for an l8 + j 2f + +1: + extui a4, a4, 0, 16 + bbci a2, 15, 2f // l16ui + + /* Sign adjustment */ + slli a4, a4, 16 + srai a4, a4, 16 // a4 contains the value + +2: + /* a4 contains the value */ + rsr a3, epc1 + addi a3, a3, 3 + wsr a3, epc1 + wsr a0, sar + rsr a0, excsave1 + + extui a2, a2, 3, 5 + blti a2, 10, .LSE_stack_reg + + movi a3, .LS_jumptable_base + addx8 a2, a2, a3 // a2 is now the address to jump to + l32i a3, sp, 0x0c + jx a2 + +.LSE_stack_reg: + addx2 a2, a2, sp + s32i a4, a2, 0 + + /* Restore all values */ + l32i a4, sp, 0x10 + l32i a3, sp, 0x0c + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + +.LSE_store_op: + s32i a5, a1, 0x14 + s32i a6, a1, 0x18 + + /* a2 -> instruction that caused the error */ + /* a3 -> unaligned address */ + extui a4, a2, 4, 4 + blti a4, 7, 1f + movi a5, .LSE_store_reg + addx8 a5, a4, a5 + jx a5 + +1: + addx4 a4, a4, sp + l32i a4, a4, 0 + +.LSE_store_data: + /* a4 contains the value */ + rsr a6, epc1 + addi a6, a6, 3 + wsr a6, epc1 + + ssa8b a3 + movi a5, -1 + bbsi a2, 12, 1f // s16 + extui a4, a4, 0, 8 + movi a6, 0xff + j 2f +1: + extui a4, a4, 0, 16 + movi a6, 0xffff +2: + sll a4, a4 // shift the value to proper offset + sll a6, a6 + xor a5, a5, a6 // a5 contains the mask + + movi a6, ~3 + and a3, a3, a6 // a3 has the aligned address + l32i a6, a3, 0 // a6 contains the data at the aligned address + and a6, a6, a5 + or a4, a6, a4 + s32i a4, a3, 0 + + /* Restore registers */ + wsr a0, sar + + l32i a6, sp, 0x18 + l32i a5, sp, 0x14 + l32i a4, sp, 0x10 + l32i a3, sp, 0x0c + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rsr a0, excsave1 + + rfe + +.LSE_store_reg: + .org .LSE_store_reg + (7 * 8) + mov a4, a7 + j .LSE_store_data + + .org .LSE_store_reg + (8 * 8) + mov a4, a8 + j .LSE_store_data + + .org .LSE_store_reg + (9 * 8) + mov a4, a9 + j .LSE_store_data + + .org .LSE_store_reg + (10 * 8) + mov a4, a10 + j .LSE_store_data + + .org .LSE_store_reg + (11 * 8) + mov a4, a11 + j .LSE_store_data + + .org .LSE_store_reg + (12 * 8) + mov a4, a12 + j .LSE_store_data + + .org .LSE_store_reg + (13 * 8) + mov a4, a13 + j .LSE_store_data + + .org .LSE_store_reg + (14 * 8) + mov a4, a14 + j .LSE_store_data + + .org .LSE_store_reg + (15 * 8) + mov a4, a15 + j .LSE_store_data + + +/* LoadStoreAlignmentCause handler: + * + * Completes unaligned 16-bit and 32-bit load/store instructions from 32-bit aligned memory region + * Called from UserExceptionVector if EXCCAUSE is LoadStoreAlignmentCause + */ + + .global AlignmentErrorHandler + .section .iram1, "ax" + + .literal_position + + .balign 4 +AlignmentErrorHandler: + .type AlignmentErrorHandler, @function + + wsr a0, depc // Save return address in depc + mov a0, sp + movi sp, LoadStoreHandlerStack + s32i a0, sp, 0x04 // Since a0 contains value of a1 + s32i a2, sp, 0x08 + s32i a3, sp, 0x0c + s32i a4, sp, 0x10 + + rsr a0, sar // Save SAR in a0 to restore later + + /* Check whether the address lies in the valid range */ + rsr a3, excvaddr + movi a4, _iram_end // End of code section of IRAM + bge a3, a4, 1f + movi a4, SOC_CACHE_APP_LOW // Check if in APP cache region + blt a3, a4, .LS_wrong_opcode + movi a4, SOC_CACHE_APP_HIGH + bge a3, a4, .LS_wrong_opcode + j 2f + +1: + movi a4, SOC_IRAM_HIGH // End of IRAM address range + bge a3, a4, .LS_wrong_opcode + +2: + /* Examine the opcode which generated the exception */ + /* Note: Instructions are in this order to avoid pipeline stalls. */ + rsr a2, epc1 + movi a4, ~3 + ssa8l a2 // sar is now correct shift for aligned read + and a2, a2, a4 // a2 now 4-byte aligned address of instruction + l32i a4, a2, 0 + l32i a2, a2, 4 + + /* a2 has the instruction that caused the error */ + src a2, a2, a4 + extui a4, a2, 0, 4 + addi a4, a4, -9 + beqz a4, .LSA_store_op + bbsi a2, 14, .LSA_store_op + + ssa8l a3 // a3 contains the unaligned address + movi a4, ~3 + and a4, a3, a4 // a4 has the aligned address + l32i a3, a4, 0 + l32i a4, a4, 4 + src a4, a4, a3 + + rsr a3, epc1 + addi a3, a3, 2 + bbsi a2, 3, 1f // l32i.n + bbci a2, 1, .LS_wrong_opcode + addi a3, a3, 1 + + bbsi a2, 13, 1f // l32 + extui a4, a4, 0, 16 + bbci a2, 15, 1f // l16ui + + /* Sign adjustment */ + slli a4, a4, 16 + srai a4, a4, 16 // a4 contains the value + +1: + wsr a3, epc1 + wsr a0, sar + rsr a0, excsave1 + + extui a2, a2, 4, 4 + blti a2, 5, .LSA_stack_reg // a3 contains the target register + + movi a3, .LS_jumptable_base + slli a2, a2, 4 + add a2, a2, a3 // a2 is now the address to jump to + l32i a3, sp, 0x0c + jx a2 + +.LSA_stack_reg: + addx4 a2, a2, sp + s32i a4, a2, 0 + + /* Restore all values */ + l32i a4, sp, 0x10 + l32i a3, sp, 0x0c + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + +/* Store instruction */ +.LSA_store_op: + s32i a5, sp, 0x14 + s32i a6, sp, 0x18 + s32i a7, sp, 0x1c + + /* a2 -> instruction that caused the error */ + /* a3 -> unaligned address */ + extui a4, a2, 4, 4 + blti a4, 8, 1f + movi a5, .LSA_store_reg + addx8 a5, a4, a5 + jx a5 + +1: + addx4 a4, a4, sp + l32i a4, a4, 0 // a4 contains the value + +.LSA_store_data: + movi a6, 0 + + rsr a7, epc1 + addi a7, a7 ,2 + bbsi a2, 3, 1f // s32i.n + bbci a2, 1, .LS_wrong_opcode + + addi a7, a7, 1 + bbsi a2, 13, 1f // s32i + + movi a5, -1 + extui a4, a4, 0, 16 + slli a6, a5, 16 // 0xffff0000 + +1: + wsr a7, epc1 + movi a5, ~3 + and a5, a3, a5 // a5 has the aligned address + + ssa8b a3 + movi a3, -1 + src a7, a6, a3 + src a3, a3, a6 + + /* Store data on lower address */ + l32i a6, a5, 0 + and a6, a6, a7 + sll a7, a4 + or a6, a6, a7 + s32i a6, a5, 0 + + /* Store data on higher address */ + l32i a7, a5, 4 + srl a6, a4 + and a3, a7, a3 + or a3, a3, a6 + s32i a3, a5, 4 + + /* Restore registers */ + wsr a0, sar + rsr a0, excsave1 + + l32i a7, sp, 0x1c + l32i a6, sp, 0x18 + l32i a5, sp, 0x14 + l32i a4, sp, 0x10 + l32i a3, sp, 0x0c + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + +.LSA_store_reg: + .org .LSA_store_reg + (8 * 8) + mov a4, a8 + j .LSA_store_data + + .org .LSA_store_reg + (9 * 8) + mov a4, a9 + j .LSA_store_data + + .org .LSA_store_reg + (10 * 8) + mov a4, a10 + j .LSA_store_data + + .org .LSA_store_reg + (11 * 8) + mov a4, a11 + j .LSA_store_data + + .org .LSA_store_reg + (12 * 8) + mov a4, a12 + j .LSA_store_data + + .org .LSA_store_reg + (13 * 8) + mov a4, a13 + j .LSA_store_data + + .org .LSA_store_reg + (14 * 8) + mov a4, a14 + j .LSA_store_data + + .org .LSA_store_reg + (15 * 8) + mov a4, a15 + j .LSA_store_data + +/* + * Common routines for both the exception handlers + */ + .balign 4 +.LS_jumptable: + /* The first 5 entries (80 bytes) of this table are unused (registers + a0..a4 are handled separately above). Rather than have a whole bunch + of wasted space, just pretend that the table starts 80 bytes + earlier in memory. */ + .set .LS_jumptable_base, .LS_jumptable - (16 * 5) + + .org .LS_jumptable_base + (16 * 5) + mov a5, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 6) + mov a6, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 7) + mov a7, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 8) + mov a8, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 9) + mov a9, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 10) + mov a10, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 11) + mov a11, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 12) + mov a12, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 13) + mov a13, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 14) + mov a14, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + + .org .LS_jumptable_base + (16 * 15) + mov a15, a4 + l32i a4, sp, 0x10 + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rfe + +.LS_wrong_opcode: + /* Reaches here if the address is in invalid range or the opcode isn't supported. + * Restore registers and jump back to _xt_user_exc + */ + wsr a0, sar + l32i a4, sp, 0x10 + l32i a3, sp, 0x0c + l32i a2, sp, 0x08 + l32i a1, sp, 0x04 + rsr a0, depc + ret // Equivalent to jx a0 diff --git a/FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_vectors.S b/FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_vectors.S index 4ae14d5c6..5c8601d1c 100644 --- a/FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_vectors.S +++ b/FreeRTOS/Source/portable/ThirdParty/GCC/Xtensa_ESP32/xtensa_vectors.S @@ -581,6 +581,11 @@ _UserExceptionVector: -------------------------------------------------------------------------------- */ +#ifdef CONFIG_ESP32_IRAM_AS_8BIT_ACCESSIBLE_MEMORY + .global LoadStoreErrorHandler + .global AlignmentErrorHandler +#endif + .section .iram1,"ax" #if XCHAL_HAVE_WINDOWED @@ -602,6 +607,20 @@ _xt_to_coproc_exc: /* never returns here - call0 is used as a jump (see note at top) */ #endif +#ifdef CONFIG_ESP32_IRAM_AS_8BIT_ACCESSIBLE_MEMORY + .align 4 +_call_loadstore_handler: + call0 LoadStoreErrorHandler + /* This will return only if wrong opcode or address out of range*/ + j .LS_exit + + .align 4 +_call_alignment_handler: + call0 AlignmentErrorHandler + /* This will return only if wrong opcode or address out of range*/ + addi a0, a0, 1 + j .LS_exit +#endif /* -------------------------------------------------------------------------------- @@ -631,6 +650,15 @@ _xt_user_exc: #endif beqi a0, EXCCAUSE_SYSCALL, _xt_to_syscall_exc +#ifdef CONFIG_ESP32_IRAM_AS_8BIT_ACCESSIBLE_MEMORY + beqi a0, EXCCAUSE_LOAD_STORE_ERROR, _call_loadstore_handler + + addi a0, a0, -1 + beqi a0, 8, _call_alignment_handler + addi a0, a0, 1 +.LS_exit: +#endif + /* Handle all other exceptions. All can have user-defined handlers. */ /* NOTE: we'll stay on the user stack for exception handling. */ -- 2.39.5