1/*************************************************************************** 2 * Copyright (c) 2024 Microsoft Corporation 3 * 4 * This program and the accompanying materials are made available under the 5 * terms of the MIT License which is available at 6 * https://opensource.org/licenses/MIT. 7 * 8 * SPDX-License-Identifier: MIT 9 **************************************************************************/ 10 11 12/**************************************************************************/ 13/**************************************************************************/ 14/** */ 15/** ThreadX Component */ 16/** */ 17/** Thread */ 18/** */ 19/**************************************************************************/ 20/**************************************************************************/ 21 22#ifdef TX_INCLUDE_USER_DEFINE_FILE 23#include "tx_user.h" 24#endif 25 26/**************************************************************************/ 27/* */ 28/* FUNCTION RELEASE */ 29/* */ 30/* _tx_thread_stack_build Cortex-Mxx/GNU */ 31/* 6.2.1 */ 32/* AUTHOR */ 33/* */ 34/* Scott Larson, Microsoft Corporation */ 35/* */ 36/* DESCRIPTION */ 37/* */ 38/* This function builds a stack frame on the supplied thread's stack. */ 39/* The stack frame results in a fake interrupt return to the supplied */ 40/* function pointer. */ 41/* */ 42/* INPUT */ 43/* */ 44/* thread_ptr Pointer to thread control blk */ 45/* function_ptr Pointer to return function */ 46/* */ 47/* OUTPUT */ 48/* */ 49/* None */ 50/* */ 51/* CALLS */ 52/* */ 53/* None */ 54/* */ 55/* CALLED BY */ 56/* */ 57/* _tx_thread_create Create thread service */ 58/* */ 59/* RELEASE HISTORY */ 60/* */ 61/* DATE NAME DESCRIPTION */ 62/* */ 63/* 09-30-2020 Scott Larson Initial Version 6.1 */ 64/* 03-08-2023 Scott Larson Include tx_user.h, */ 65/* resulting in version 6.2.1 */ 66/* */ 67/**************************************************************************/ 68// VOID _tx_thread_stack_build(TX_THREAD *thread_ptr, VOID (*function_ptr)(VOID)) 69// { 70 .section .text 71 .balign 4 72 .syntax unified 73 .eabi_attribute Tag_ABI_align_preserved, 1 74 .global _tx_thread_stack_build 75 .thumb_func 76.type _tx_thread_stack_build, function 77_tx_thread_stack_build: 78 /* Build a fake interrupt frame. The form of the fake interrupt stack 79 on the Cortex-M should look like the following after it is built: 80 81 Stack Top: 82 LR Interrupted LR (LR at time of PENDSV) 83 r4 Initial value for r4 84 r5 Initial value for r5 85 r6 Initial value for r6 86 r7 Initial value for r7 87 r8 Initial value for r8 88 r9 Initial value for r9 89 r10 Initial value for r10 90 r11 Initial value for r11 91 r0 Initial value for r0 (Hardware stack starts here!!) 92 r1 Initial value for r1 93 r2 Initial value for r2 94 r3 Initial value for r3 95 r12 Initial value for r12 96 lr Initial value for lr 97 pc Initial value for pc 98 xPSR Initial value for xPSR 99 100 Stack Bottom: (higher memory address) */ 101 102 LDR r2, [r0, #16] // Pickup end of stack area 103 BIC r2, r2, #0x7 // Align frame for 8-byte alignment 104 SUB r2, r2, #68 // Subtract frame size 105#ifdef TX_SINGLE_MODE_SECURE 106 LDR r3, =0xFFFFFFFD // Build initial LR value for secure mode 107#else 108 LDR r3, =0xFFFFFFBC // Build initial LR value to return to non-secure PSP 109#endif 110 STR r3, [r2, #0] // Save on the stack 111 112 /* Actually build the stack frame. */ 113 114 MOV r3, #0 // Build initial register value 115 STR r3, [r2, #4] // Store initial r4 116 STR r3, [r2, #8] // Store initial r5 117 STR r3, [r2, #12] // Store initial r6 118 STR r3, [r2, #16] // Store initial r7 119 STR r3, [r2, #20] // Store initial r8 120 STR r3, [r2, #24] // Store initial r9 121 STR r3, [r2, #28] // Store initial r10 122 STR r3, [r2, #32] // Store initial r11 123 124 /* Hardware stack follows. */ 125 126 STR r3, [r2, #36] // Store initial r0 127 STR r3, [r2, #40] // Store initial r1 128 STR r3, [r2, #44] // Store initial r2 129 STR r3, [r2, #48] // Store initial r3 130 STR r3, [r2, #52] // Store initial r12 131 MOV r3, #0xFFFFFFFF // Poison EXC_RETURN value 132 STR r3, [r2, #56] // Store initial lr 133 STR r1, [r2, #60] // Store initial pc 134 MOV r3, #0x01000000 // Only T-bit need be set 135 STR r3, [r2, #64] // Store initial xPSR 136 137 /* Setup stack pointer. */ 138 // thread_ptr -> tx_thread_stack_ptr = r2; 139 140 STR r2, [r0, #8] // Save stack pointer in thread's 141 // control block 142 BX lr // Return to caller 143// } 144 .end 145
