1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <plat/cmsis.h>
18 #include <plat/plat.h>
19 #include <plat/pwr.h>
20 #include <plat/wdt.h>
21 #include <syscall.h>
22 #include <string.h>
23 #include <seos.h>
24 #include <heap.h>
25 #include <cpu.h>
26 #include <util.h>
27 #include <reset.h>
28
29
30 #define HARD_FAULT_DROPBOX_MAGIC_MASK 0xFFFFC000
31 #define HARD_FAULT_DROPBOX_MAGIC_VAL 0x31414000
32 #define HARD_FAULT_DROPBOX_MAGIC_HAVE_DROP 0x00002000
33 #define HARD_FAULT_DROPBOX_MAGIC_DATA_MASK 0x00001FFF
34
35 struct RamPersistedDataAndDropbox {
36 uint32_t magic; // and part of dropbox
37 uint32_t r[16];
38 uint32_t sr_hfsr_cfsr_lo;
39 uint32_t bits;
40 uint16_t tid;
41 uint16_t trig:2;
42 uint16_t RFU:14;
43 };
44
45 /* //if your device persists ram, you can use this instead:
46 * static struct RamPersistedDataAndDropbox* getPersistedData(void)
47 * {
48 * static struct RamPersistedDataAndDropbox __attribute__((section(".neverinit"))) dbx;
49 * return &dbx;
50 * }
51 */
52
getPersistedData(void)53 static struct RamPersistedDataAndDropbox* getPersistedData(void)
54 {
55 uint32_t bytes = 0;
56 void *loc = platGetPersistentRamStore(&bytes);
57
58 return bytes >= sizeof(struct RamPersistedDataAndDropbox) ? (struct RamPersistedDataAndDropbox*)loc : NULL;
59 }
60
getInitedPersistedData(void)61 static struct RamPersistedDataAndDropbox* getInitedPersistedData(void)
62 {
63 struct RamPersistedDataAndDropbox* dbx = getPersistedData();
64
65 if ((dbx->magic & HARD_FAULT_DROPBOX_MAGIC_MASK) != HARD_FAULT_DROPBOX_MAGIC_VAL) {
66 dbx->bits = 0;
67 dbx->magic = HARD_FAULT_DROPBOX_MAGIC_VAL;
68 }
69
70 return dbx;
71 }
72
cpuInit(void)73 void cpuInit(void)
74 {
75 /* set SVC to be highest possible priority */
76 NVIC_SetPriority(SVCall_IRQn, 0xff);
77
78 /* FPU on */
79 SCB->CPACR |= 0x00F00000;
80 }
81
82 //pack all our SR regs into 45 bits
cpuPackSrBits(uint32_t * dstLo,uint32_t * dstHi,uint32_t sr,uint32_t hfsr,uint32_t cfsr)83 static void cpuPackSrBits(uint32_t *dstLo, uint32_t *dstHi, uint32_t sr, uint32_t hfsr, uint32_t cfsr)
84 {
85 //mask of useful bits:
86 // SR: 11111111 00000000 11111101 11111111 (total of 23 bits)
87 // HFSR: 01000000 00000000 00000000 00000010 (total of 2 bits)
88 // CFSR: 00000011 00001111 10111111 10111111 (total of 20 bits)
89 // so our total is 45 bits. we pack this into 2 longs (for now)
90
91 sr &= 0xFF00FDFF;
92 hfsr &= 0x40000002;
93 cfsr &= 0x030FBFBF;
94
95 *dstLo = sr | ((cfsr << 4) & 0x00FF0000) | (hfsr >> 12) | (hfsr << 8);
96 *dstHi = ((cfsr & 0x01000000) >> 18) | ((cfsr & 0x02000000) >> 13) | (cfsr & 0x00000fff);
97 }
98
99 //unpack the SR bits
cpuUnpackSrBits(uint32_t srcLo,uint32_t srcHi,uint32_t * srP,uint32_t * hfsrP,uint32_t * cfsrP)100 static void cpuUnpackSrBits(uint32_t srcLo, uint32_t srcHi, uint32_t *srP, uint32_t *hfsrP, uint32_t *cfsrP)
101 {
102 *srP = srcLo & 0xFF00FDFF;
103 *hfsrP = ((srcLo << 12) & 0x40000000) | ((srcLo >> 8) & 0x00000002);
104 *cfsrP = ((srcLo & 0x00FB0000) >> 4) | (srcHi & 0x0FBF) | ((srcHi << 13) & 0x02000000) | ((srcHi << 18) & 0x01000000);
105 }
106
cpuDbxDump(struct RamPersistedDataAndDropbox * dbx)107 static void cpuDbxDump(struct RamPersistedDataAndDropbox *dbx)
108 {
109 uint32_t i, hfsr, cfsr, sr, code;
110 const char *trigName;
111 static const char *trigNames[] = { "UNKNOWN", "HARD FAULT", "WDT" };
112
113 if (dbx) {
114 for (i = 0; i < 8; i++)
115 osLog(LOG_ERROR, " R%02lu = 0x%08lX R%02lu = 0x%08lX\n",
116 i, dbx->r[i], i + 8, dbx->r[i+8]);
117
118 cpuUnpackSrBits(dbx->sr_hfsr_cfsr_lo, dbx->magic & HARD_FAULT_DROPBOX_MAGIC_DATA_MASK, &sr, &hfsr, &cfsr);
119
120 osLog(LOG_ERROR, " xPSR = 0x%08lX HFSR = 0x%08lX\n", sr, hfsr);
121 osLog(LOG_ERROR, " CFSR = 0x%08lX BITS = 0x%08lX\n", cfsr, dbx->bits);
122 // reboot source (if known), reported as TRIG
123 // so far we have 2 reboot sources reported here:
124 // 1 - HARD FAULT
125 // 2 - WDT
126 code = dbx->trig;
127 trigName = trigNames[code < ARRAY_SIZE(trigNames) ? code : 0];
128 osLog(LOG_ERROR, " TID = 0x%04" PRIX16 " TRIG = 0x%04" PRIX16 " [%s]\n", dbx->tid, dbx->trig, trigName);
129 }
130 }
131
cpuInitLate(void)132 void cpuInitLate(void)
133 {
134 struct RamPersistedDataAndDropbox *dbx = getInitedPersistedData();
135 uint32_t reason = pwrResetReason();
136 const char *reasonDesc = "";
137 enum LogLevel level = LOG_INFO;
138
139 // if we detected WDT reboot reason, we are likely not having data in dropbox
140 // All we can do is report that WDT reset happened
141 if ((reason & (RESET_WINDOW_WATCHDOG|RESET_INDEPENDENT_WATCHDOG)) != 0) {
142 reasonDesc = "; HW WDT RESET";
143 level = LOG_ERROR;
144 }
145
146 osLog(level, "Reboot reason: 0x%08" PRIX32 "%s\n", reason, reasonDesc);
147
148 /* print and clear dropbox */
149 if (dbx->magic & HARD_FAULT_DROPBOX_MAGIC_HAVE_DROP) {
150 osLog(LOG_INFO, "Dropbox not empty. Contents:\n");
151 cpuDbxDump(dbx);
152 }
153 dbx->magic &=~ HARD_FAULT_DROPBOX_MAGIC_HAVE_DROP;
154 }
155
cpuRamPersistentBitGet(uint32_t which)156 bool cpuRamPersistentBitGet(uint32_t which)
157 {
158 struct RamPersistedDataAndDropbox *dbx = getInitedPersistedData();
159
160 return (which < CPU_NUM_PERSISTENT_RAM_BITS) && ((dbx->bits >> which) & 1);
161 }
162
cpuRamPersistentBitSet(uint32_t which,bool on)163 void cpuRamPersistentBitSet(uint32_t which, bool on)
164 {
165 struct RamPersistedDataAndDropbox *dbx = getInitedPersistedData();
166
167 if (which < CPU_NUM_PERSISTENT_RAM_BITS) {
168 if (on)
169 dbx->bits |= (1ULL << which);
170 else
171 dbx->bits &=~ (1ULL << which);
172 }
173 }
174
cpuIntsOff(void)175 uint64_t cpuIntsOff(void)
176 {
177 uint32_t state;
178
179 asm volatile (
180 "mrs %0, PRIMASK \n"
181 "cpsid i \n"
182 :"=r"(state)
183 );
184
185 return state;
186 }
187
cpuIntsOn(void)188 uint64_t cpuIntsOn(void)
189 {
190 uint32_t state;
191
192 asm volatile (
193 "mrs %0, PRIMASK \n"
194 "cpsie i \n"
195 :"=r"(state)
196 );
197
198 return state;
199 }
200
cpuIntsRestore(uint64_t state)201 void cpuIntsRestore(uint64_t state)
202 {
203
204 asm volatile(
205 "msr PRIMASK, %0 \n"
206 ::"r"((uint32_t)state)
207 );
208 }
209
210 /*
211 * Stack layout for HW interrupt handlers [ARM7-M]
212 * ===============================================
213 * orig_SP[8...25] = FPU state (S0..S15, FPSCR, Reserved) [if enabled]
214 * orig_SP[7] = xPSR
215 * orig_SP[6] = ReturnAddress
216 * orig_SP[5] = LR (R14)
217 * orig_SP[4] = R12
218 * orig_SP[3..0] = R3..R0
219 *
220 * upon entry, new value of LR is calculated as follows:
221 * LR := 0xFFFFFFE0 | <Control.FPCA ? 0 : 0x10> | <Mode_Handler ? 0 : 8> | <SPSEL ? 4 : 0> | 0x01
222 *
223 * upon exit, PC value is interpreted according to the same rule (see LR above)
224 * if bits 28..31 of PC equal 0xF, return from interrupt is executed
225 * this way, "bx lr" would perform return from interrupt to the previous state
226 */
227
syscallHandler(uintptr_t * excRegs)228 static void __attribute__((used)) syscallHandler(uintptr_t *excRegs)
229 {
230 uint16_t *svcPC = ((uint16_t *)(excRegs[6])) - 1;
231 uint32_t svcNo = (*svcPC) & 0xFF;
232 uint32_t syscallNr = excRegs[0];
233 SyscallFunc handler;
234 va_list args_long = *(va_list*)(excRegs + 1);
235 uintptr_t *fastParams = excRegs + 1;
236 va_list args_fast = *(va_list*)(&fastParams);
237
238 if (svcNo > 1)
239 osLog(LOG_WARN, "Unknown SVC 0x%02lX called at 0x%08lX\n", svcNo, (unsigned long)svcPC);
240 else if (!(handler = syscallGetHandler(syscallNr)))
241 osLog(LOG_WARN, "Unknown syscall 0x%08lX called at 0x%08lX\n", (unsigned long)syscallNr, (unsigned long)svcPC);
242 else
243 handler(excRegs, svcNo ? args_fast : args_long);
244 }
245
246 void SVC_Handler(void);
SVC_Handler(void)247 void __attribute__((naked)) SVC_Handler(void)
248 {
249 asm volatile(
250 "tst lr, #4 \n"
251 "ite eq \n"
252 "mrseq r0, msp \n"
253 "mrsne r0, psp \n"
254 "b syscallHandler \n"
255 );
256 }
257
logHardFault(uintptr_t * excRegs,uintptr_t * otherRegs,bool tinyStack,uint32_t code)258 static void __attribute__((used)) logHardFault(uintptr_t *excRegs, uintptr_t* otherRegs, bool tinyStack, uint32_t code)
259 {
260 struct RamPersistedDataAndDropbox *dbx = getInitedPersistedData();
261 uint32_t i, hi;
262
263 wdtPing();
264
265 for (i = 0; i < 4; i++)
266 dbx->r[i] = excRegs[i];
267 for (i = 0; i < 8; i++)
268 dbx->r[i + 4] = otherRegs[i];
269 dbx->r[12] = excRegs[4];
270 dbx->r[13] = (uint32_t)(excRegs + 8);
271 dbx->r[14] = excRegs[5];
272 dbx->r[15] = excRegs[6];
273
274 cpuPackSrBits(&dbx->sr_hfsr_cfsr_lo, &hi, excRegs[7], SCB->HFSR, SCB->CFSR);
275 dbx->magic |= HARD_FAULT_DROPBOX_MAGIC_HAVE_DROP | (hi & HARD_FAULT_DROPBOX_MAGIC_DATA_MASK);
276 dbx->tid = osGetCurrentTid();
277 dbx->trig = code;
278
279 if (!tinyStack) {
280 osLog(LOG_ERROR, "*HARD FAULT*\n");
281 cpuDbxDump(dbx);
282 }
283
284 NVIC_SystemReset();
285 }
286
287 static uint32_t __attribute__((used)) hfStack[16];
288
289 void cpuCommonFaultCode(void);
cpuCommonFaultCode(void)290 void __attribute__((naked)) cpuCommonFaultCode(void)
291 {
292 // r0 contains Fault IRQ code
293 asm volatile(
294 "ldr r3, =__stack_bottom + 64 \n"
295 "cmp sp, r3 \n"
296 "itte le \n"
297 "ldrle sp, =hfStack + 64 \n"
298 "movle r2, #1 \n"
299 "movgt r2, #0 \n"
300 "mov r3, r0 \n"
301 "tst lr, #4 \n"
302 "ite eq \n"
303 "mrseq r0, msp \n"
304 "mrsne r0, psp \n"
305 "push {r4-r11} \n"
306 "mov r1, sp \n"
307 "b logHardFault \n"
308 );
309 }
310
311 void HardFault_Handler(void);
HardFault_Handler(void)312 void __attribute__((naked)) HardFault_Handler(void)
313 {
314 asm volatile(
315 "mov r0, #1 \n"
316 "b cpuCommonFaultCode \n"
317 );
318 }
319