1 /*
2 * FreeRTOS V202212.00
3 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a copy of
6 * this software and associated documentation files (the "Software"), to deal in
7 * the Software without restriction, including without limitation the rights to
8 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
9 * the Software, and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in all
13 * copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
17 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
18 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
19 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * https://www.FreeRTOS.org
23 * https://github.com/FreeRTOS
24 *
25 */
26
27 #include <stdint.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31
32 extern void vPortSVCHandler( void );
33 extern void xPortPendSVHandler( void );
34 extern void xPortSysTickHandler( void );
35 extern void uart_init( void );
36 extern int main( void );
37
38 void _start( void );
39 void EthernetISR( void );
40 void Reset_Handler( void );
41
42 extern uint32_t _estack, _sidata, _sdata, _edata, _sbss, _ebss;
43
44 /* Prevent optimization so gcc does not replace code with memcpy */
45 __attribute__( ( optimize( "O0" ) ) )
46 __attribute__( ( naked ) )
Reset_Handler(void)47 void Reset_Handler( void )
48 {
49 /* set stack pointer */
50 __asm volatile ( "ldr r0, =_estack" );
51 __asm volatile ( "mov sp, r0" );
52
53 /* copy .data section from flash to RAM */
54 for( uint32_t * src = &_sidata, * dest = &_sdata; dest < &_edata; )
55 {
56 *dest++ = *src++;
57 }
58
59 /* zero out .bss section */
60 for( uint32_t * dest = &_sbss; dest < &_ebss; )
61 {
62 *dest++ = 0;
63 }
64
65 /* jump to board initialisation */
66 _start();
67 }
68
prvGetRegistersFromStack(uint32_t * pulFaultStackAddress)69 __attribute__( ( used ) ) static void prvGetRegistersFromStack( uint32_t * pulFaultStackAddress )
70 {
71 /* These are volatile to try and prevent the compiler/linker optimizing them
72 * away as the variables never actually get used. If the debugger won't show the
73 * values of the variables, make them global my moving their declaration outside
74 * of this function. */
75 volatile uint32_t r0;
76 volatile uint32_t r1;
77 volatile uint32_t r2;
78 volatile uint32_t r3;
79 volatile uint32_t r12;
80 volatile uint32_t lr; /* Link register. */
81 volatile uint32_t pc; /* Program counter. */
82 volatile uint32_t psr; /* Program status register. */
83
84 r0 = pulFaultStackAddress[ 0 ];
85 r1 = pulFaultStackAddress[ 1 ];
86 r2 = pulFaultStackAddress[ 2 ];
87 r3 = pulFaultStackAddress[ 3 ];
88
89 r12 = pulFaultStackAddress[ 4 ];
90 lr = pulFaultStackAddress[ 5 ];
91 pc = pulFaultStackAddress[ 6 ];
92 psr = pulFaultStackAddress[ 7 ];
93
94 /* When the following line is hit, the variables contain the register values. */
95 for( ; ; )
96 {
97 }
98
99 /* Remove the warning about unused variables. */
100 ( void ) r0;
101 ( void ) r1;
102 ( void ) r2;
103 ( void ) r3;
104 ( void ) r12;
105 ( void ) lr;
106 ( void ) pc;
107 ( void ) psr;
108 }
109
110 static void Default_Handler( void ) __attribute__( ( naked ) );
Default_Handler(void)111 void Default_Handler( void )
112 {
113 __asm volatile
114 (
115 "Default_Handler:\n"
116 " ldr r3, =0xe000ed04\n"
117 " ldr r2, [r3, #0]\n"
118 " uxtb r2, r2\n"
119 "Infinite_Loop:\n"
120 " b Infinite_Loop\n"
121 ".size Default_Handler, .-Default_Handler\n"
122 ".ltorg\n"
123 );
124 }
125
126 static void Default_Handler2( void ) __attribute__( ( naked ) );
Default_Handler2(void)127 void Default_Handler2( void )
128 {
129 __asm volatile
130 (
131 " tst lr, #4 \n"
132 " ite eq \n"
133 " mrseq r0, msp \n"
134 " mrsne r0, psp \n"
135 " ldr r1, [r0, #24] \n"
136 " ldr r2, =prvGetRegistersFromStack \n"
137 " bx r2 \n"
138 " .ltorg \n"
139 );
140 }
141
Default_Handler3(void)142 static void Default_Handler3( void )
143 {
144 for( ; ; )
145 {
146 }
147 }
148
Default_Handler4(void)149 static void Default_Handler4( void )
150 {
151 for( ; ; )
152 {
153 }
154 }
155
Default_Handler5(void)156 static void Default_Handler5( void )
157 {
158 for( ; ; )
159 {
160 }
161 }
162
Default_Handler6(void)163 static void Default_Handler6( void )
164 {
165 for( ; ; )
166 {
167 }
168 }
169
170 const uint32_t * const isr_vector[] __attribute__( ( section( ".isr_vector" ), used ) ) =
171 {
172 ( uint32_t * ) &_estack,
173 ( uint32_t * ) &Reset_Handler, /* Reset -15 */
174 ( uint32_t * ) &Default_Handler, /* NMI_Handler -14 */
175 ( uint32_t * ) &Default_Handler2, /* HardFault_Handler -13 */
176 ( uint32_t * ) &Default_Handler3, /* MemManage_Handler -12 */
177 ( uint32_t * ) &Default_Handler4, /* BusFault_Handler -11 */
178 ( uint32_t * ) &Default_Handler5, /* UsageFault_Handler -10 */
179 0, /* reserved */
180 0, /* reserved */
181 0, /* reserved */
182 0, /* reserved -6 */
183 ( uint32_t * ) &vPortSVCHandler, /* SVC_Handler -5 */
184 ( uint32_t * ) &Default_Handler6, /* DebugMon_Handler -4 */
185 0, /* reserved */
186 ( uint32_t * ) &xPortPendSVHandler, /* PendSV handler -2 */
187 ( uint32_t * ) &xPortSysTickHandler, /* SysTick_Handler -1 */
188 0, /* uart0 receive 0 */
189 0, /* uart0 transmit */
190 0, /* uart1 receive */
191 0, /* uart1 transmit */
192 0, /* uart 2 receive */
193 0, /* uart 2 transmit */
194 0, /* GPIO 0 combined interrupt */
195 0, /* GPIO 2 combined interrupt */
196 0, /* Timer 0 */
197 0, /* Timer 1 */
198 0, /* Dial Timer */
199 0, /* SPI0 SPI1 */
200 0, /* uart overflow 1 2,3 12 */
201 ( uint32_t * ) &EthernetISR, /* Ethernet 13 */
202 };
203
_start(void)204 void _start( void )
205 {
206 uart_init();
207 main();
208 exit( 0 );
209 }
210
exit(int status)211 __attribute__( ( naked ) ) void exit( int status )
212 {
213 /* Force qemu to exit using ARM Semihosting */
214 __asm volatile (
215 "mov r1, r0\n"
216 "cmp r1, #0\n"
217 "bne .notclean\n"
218 "ldr r1, =0x20026\n" /* ADP_Stopped_ApplicationExit, a clean exit */
219 ".notclean:\n"
220 "movs r0, #0x18\n" /* SYS_EXIT */
221 "bkpt 0xab\n"
222 "end: b end\n"
223 ".ltorg"
224 );
225
226 ( void ) status;
227 }
228