Bob Seque / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

api/CThunk.h@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:9b334a45a8ff 1 /* General C++ Object Thunking class
bogdanm 0:9b334a45a8ff 2 *
bogdanm 0:9b334a45a8ff 3 * - allows direct callbacks to non-static C++ class functions
bogdanm 0:9b334a45a8ff 4 * - keeps track for the corresponding class instance
bogdanm 0:9b334a45a8ff 5 * - supports an optional context parameter for the called function
bogdanm 0:9b334a45a8ff 6 * - ideally suited for class object receiving interrupts (NVIC_SetVector)
bogdanm 0:9b334a45a8ff 7 *
bogdanm 0:9b334a45a8ff 8 * Copyright (c) 2014-2015 ARM Limited
bogdanm 0:9b334a45a8ff 9 *
bogdanm 0:9b334a45a8ff 10 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 0:9b334a45a8ff 11 * you may not use this file except in compliance with the License.
bogdanm 0:9b334a45a8ff 12 * You may obtain a copy of the License at
bogdanm 0:9b334a45a8ff 13 *
bogdanm 0:9b334a45a8ff 14 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 0:9b334a45a8ff 15 *
bogdanm 0:9b334a45a8ff 16 * Unless required by applicable law or agreed to in writing, software
bogdanm 0:9b334a45a8ff 17 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 0:9b334a45a8ff 18 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 0:9b334a45a8ff 19 * See the License for the specific language governing permissions and
bogdanm 0:9b334a45a8ff 20 * limitations under the License.
bogdanm 0:9b334a45a8ff 21 */
bogdanm 0:9b334a45a8ff 22 #ifndef __CTHUNK_H__
bogdanm 0:9b334a45a8ff 23 #define __CTHUNK_H__
bogdanm 0:9b334a45a8ff 24
bogdanm 0:9b334a45a8ff 25 #define CTHUNK_ADDRESS 1
bogdanm 0:9b334a45a8ff 26
bogdanm 0:9b334a45a8ff 27 #if defined(__CORTEX_M3) || defined(__CORTEX_M4) || defined(__thumb2__)
bogdanm 0:9b334a45a8ff 28 #define CTHUNK_VARIABLES volatile uint32_t code[1]
bogdanm 0:9b334a45a8ff 29 /**
bogdanm 0:9b334a45a8ff 30 * CTHUNK disassembly for Cortex-M3/M4 (thumb2):
bogdanm 0:9b334a45a8ff 31 * * ldm.w pc,{r0,r1,r2,pc}
bogdanm 0:9b334a45a8ff 32 *
bogdanm 0:9b334a45a8ff 33 * This instruction loads the arguments for the static thunking function to r0-r2, and
bogdanm 0:9b334a45a8ff 34 * branches to that function by loading its address into PC.
bogdanm 0:9b334a45a8ff 35 *
bogdanm 0:9b334a45a8ff 36 * This is safe for both regular calling and interrupt calling, since it only touches scratch registers
bogdanm 0:9b334a45a8ff 37 * which should be saved by the caller, and are automatically saved as part of the IRQ context switch.
bogdanm 0:9b334a45a8ff 38 */
bogdanm 0:9b334a45a8ff 39 #define CTHUNK_ASSIGMENT m_thunk.code[0] = 0x8007E89F
bogdanm 0:9b334a45a8ff 40
bogdanm 0:9b334a45a8ff 41 #elif defined(__CORTEX_M0PLUS) || defined(__CORTEX_M0)
bogdanm 0:9b334a45a8ff 42 /*
bogdanm 0:9b334a45a8ff 43 * CTHUNK disassembly for Cortex M0 (thumb):
bogdanm 0:9b334a45a8ff 44 * * push {r0,r1,r2,r3,r4,lr} save touched registers and return address
bogdanm 0:9b334a45a8ff 45 * * movs r4,#4 set up address to load arguments from (immediately following this code block) (1)
bogdanm 0:9b334a45a8ff 46 * * add r4,pc set up address to load arguments from (immediately following this code block) (2)
bogdanm 0:9b334a45a8ff 47 * * ldm r4!,{r0,r1,r2,r3} load arguments for static thunk function
bogdanm 0:9b334a45a8ff 48 * * blx r3 call static thunk function
bogdanm 0:9b334a45a8ff 49 * * pop {r0,r1,r2,r3,r4,pc} restore scratch registers and return from function
bogdanm 0:9b334a45a8ff 50 */
bogdanm 0:9b334a45a8ff 51 #define CTHUNK_VARIABLES volatile uint32_t code[3]
bogdanm 0:9b334a45a8ff 52 #define CTHUNK_ASSIGMENT do { \
bogdanm 0:9b334a45a8ff 53 m_thunk.code[0] = 0x2404B51F; \
bogdanm 0:9b334a45a8ff 54 m_thunk.code[1] = 0xCC0F447C; \
bogdanm 0:9b334a45a8ff 55 m_thunk.code[2] = 0xBD1F4798; \
bogdanm 0:9b334a45a8ff 56 } while (0)
bogdanm 0:9b334a45a8ff 57
bogdanm 0:9b334a45a8ff 58 #else
bogdanm 0:9b334a45a8ff 59 #error "Target is not currently suported."
bogdanm 0:9b334a45a8ff 60 #endif
bogdanm 0:9b334a45a8ff 61
bogdanm 0:9b334a45a8ff 62 /* IRQ/Exception compatible thunk entry function */
bogdanm 0:9b334a45a8ff 63 typedef void (*CThunkEntry)(void);
bogdanm 0:9b334a45a8ff 64
bogdanm 0:9b334a45a8ff 65 template<class T>
bogdanm 0:9b334a45a8ff 66 class CThunk
bogdanm 0:9b334a45a8ff 67 {
bogdanm 0:9b334a45a8ff 68 public:
bogdanm 0:9b334a45a8ff 69 typedef void (T::*CCallbackSimple)(void);
bogdanm 0:9b334a45a8ff 70 typedef void (T::*CCallback)(void* context);
bogdanm 0:9b334a45a8ff 71
bogdanm 0:9b334a45a8ff 72 inline CThunk(T *instance)
bogdanm 0:9b334a45a8ff 73 {
bogdanm 0:9b334a45a8ff 74 init(instance, NULL, NULL);
bogdanm 0:9b334a45a8ff 75 }
bogdanm 0:9b334a45a8ff 76
bogdanm 0:9b334a45a8ff 77 inline CThunk(T *instance, CCallback callback)
bogdanm 0:9b334a45a8ff 78 {
bogdanm 0:9b334a45a8ff 79 init(instance, callback, NULL);
bogdanm 0:9b334a45a8ff 80 }
bogdanm 0:9b334a45a8ff 81
bogdanm 0:9b334a45a8ff 82 ~CThunk() {
bogdanm 0:9b334a45a8ff 83
bogdanm 0:9b334a45a8ff 84 }
bogdanm 0:9b334a45a8ff 85
bogdanm 0:9b334a45a8ff 86 inline CThunk(T *instance, CCallbackSimple callback)
bogdanm 0:9b334a45a8ff 87 {
bogdanm 0:9b334a45a8ff 88 init(instance, (CCallback)callback, NULL);
bogdanm 0:9b334a45a8ff 89 }
bogdanm 0:9b334a45a8ff 90
bogdanm 0:9b334a45a8ff 91 inline CThunk(T &instance, CCallback callback)
bogdanm 0:9b334a45a8ff 92 {
bogdanm 0:9b334a45a8ff 93 init(instance, callback, NULL);
bogdanm 0:9b334a45a8ff 94 }
bogdanm 0:9b334a45a8ff 95
bogdanm 0:9b334a45a8ff 96 inline CThunk(T &instance, CCallbackSimple callback)
bogdanm 0:9b334a45a8ff 97 {
bogdanm 0:9b334a45a8ff 98 init(instance, (CCallback)callback, NULL);
bogdanm 0:9b334a45a8ff 99 }
bogdanm 0:9b334a45a8ff 100
bogdanm 0:9b334a45a8ff 101 inline CThunk(T &instance, CCallback callback, void* context)
bogdanm 0:9b334a45a8ff 102 {
bogdanm 0:9b334a45a8ff 103 init(instance, callback, context);
bogdanm 0:9b334a45a8ff 104 }
bogdanm 0:9b334a45a8ff 105
bogdanm 0:9b334a45a8ff 106 inline void callback(CCallback callback)
bogdanm 0:9b334a45a8ff 107 {
bogdanm 0:9b334a45a8ff 108 m_callback = callback;
bogdanm 0:9b334a45a8ff 109 }
bogdanm 0:9b334a45a8ff 110
bogdanm 0:9b334a45a8ff 111 inline void callback(CCallbackSimple callback)
bogdanm 0:9b334a45a8ff 112 {
bogdanm 0:9b334a45a8ff 113 m_callback = (CCallback)callback;
bogdanm 0:9b334a45a8ff 114 }
bogdanm 0:9b334a45a8ff 115
bogdanm 0:9b334a45a8ff 116 inline void context(void* context)
bogdanm 0:9b334a45a8ff 117 {
bogdanm 0:9b334a45a8ff 118 m_thunk.context = (uint32_t)context;
bogdanm 0:9b334a45a8ff 119 }
bogdanm 0:9b334a45a8ff 120
bogdanm 0:9b334a45a8ff 121 inline void context(uint32_t context)
bogdanm 0:9b334a45a8ff 122 {
bogdanm 0:9b334a45a8ff 123 m_thunk.context = context;
bogdanm 0:9b334a45a8ff 124 }
bogdanm 0:9b334a45a8ff 125
bogdanm 0:9b334a45a8ff 126 inline uint32_t entry(void)
bogdanm 0:9b334a45a8ff 127 {
bogdanm 0:9b334a45a8ff 128 return (((uint32_t)&m_thunk)|CTHUNK_ADDRESS);
bogdanm 0:9b334a45a8ff 129 }
bogdanm 0:9b334a45a8ff 130
bogdanm 0:9b334a45a8ff 131 /* get thunk entry point for connecting rhunk to an IRQ table */
bogdanm 0:9b334a45a8ff 132 inline operator CThunkEntry(void)
bogdanm 0:9b334a45a8ff 133 {
bogdanm 0:9b334a45a8ff 134 return (CThunkEntry)entry();
bogdanm 0:9b334a45a8ff 135 }
bogdanm 0:9b334a45a8ff 136
bogdanm 0:9b334a45a8ff 137 /* get thunk entry point for connecting rhunk to an IRQ table */
bogdanm 0:9b334a45a8ff 138 inline operator uint32_t(void)
bogdanm 0:9b334a45a8ff 139 {
bogdanm 0:9b334a45a8ff 140 return entry();
bogdanm 0:9b334a45a8ff 141 }
bogdanm 0:9b334a45a8ff 142
bogdanm 0:9b334a45a8ff 143 /* simple test function */
bogdanm 0:9b334a45a8ff 144 inline void call(void)
bogdanm 0:9b334a45a8ff 145 {
bogdanm 0:9b334a45a8ff 146 (((CThunkEntry)(entry()))());
bogdanm 0:9b334a45a8ff 147 }
bogdanm 0:9b334a45a8ff 148
bogdanm 0:9b334a45a8ff 149 private:
bogdanm 0:9b334a45a8ff 150 T* m_instance;
bogdanm 0:9b334a45a8ff 151 volatile CCallback m_callback;
bogdanm 0:9b334a45a8ff 152
bogdanm 0:9b334a45a8ff 153 // TODO: this needs proper fix, to refactor toolchain header file and all its use
bogdanm 0:9b334a45a8ff 154 // PACKED there is not defined properly for IAR
bogdanm 0:9b334a45a8ff 155 #if defined (__ICCARM__)
bogdanm 0:9b334a45a8ff 156 typedef __packed struct
bogdanm 0:9b334a45a8ff 157 {
bogdanm 0:9b334a45a8ff 158 CTHUNK_VARIABLES;
bogdanm 0:9b334a45a8ff 159 volatile uint32_t instance;
bogdanm 0:9b334a45a8ff 160 volatile uint32_t context;
bogdanm 0:9b334a45a8ff 161 volatile uint32_t callback;
bogdanm 0:9b334a45a8ff 162 volatile uint32_t trampoline;
bogdanm 0:9b334a45a8ff 163 } CThunkTrampoline;
bogdanm 0:9b334a45a8ff 164 #else
bogdanm 0:9b334a45a8ff 165 typedef struct
bogdanm 0:9b334a45a8ff 166 {
bogdanm 0:9b334a45a8ff 167 CTHUNK_VARIABLES;
bogdanm 0:9b334a45a8ff 168 volatile uint32_t instance;
bogdanm 0:9b334a45a8ff 169 volatile uint32_t context;
bogdanm 0:9b334a45a8ff 170 volatile uint32_t callback;
bogdanm 0:9b334a45a8ff 171 volatile uint32_t trampoline;
bogdanm 0:9b334a45a8ff 172 } __attribute__((__packed__)) CThunkTrampoline;
bogdanm 0:9b334a45a8ff 173 #endif
bogdanm 0:9b334a45a8ff 174
bogdanm 0:9b334a45a8ff 175 static void trampoline(T* instance, void* context, CCallback* callback)
bogdanm 0:9b334a45a8ff 176 {
bogdanm 0:9b334a45a8ff 177 if(instance && *callback) {
bogdanm 0:9b334a45a8ff 178 (static_cast<T*>(instance)->**callback)(context);
bogdanm 0:9b334a45a8ff 179 }
bogdanm 0:9b334a45a8ff 180 }
bogdanm 0:9b334a45a8ff 181
bogdanm 0:9b334a45a8ff 182 volatile CThunkTrampoline m_thunk;
bogdanm 0:9b334a45a8ff 183
bogdanm 0:9b334a45a8ff 184 inline void init(T *instance, CCallback callback, void* context)
bogdanm 0:9b334a45a8ff 185 {
bogdanm 0:9b334a45a8ff 186 /* remember callback - need to add this level of redirection
bogdanm 0:9b334a45a8ff 187 as pointer size for member functions differs between platforms */
bogdanm 0:9b334a45a8ff 188 m_callback = callback;
bogdanm 0:9b334a45a8ff 189
bogdanm 0:9b334a45a8ff 190 /* populate thunking trampoline */
bogdanm 0:9b334a45a8ff 191 CTHUNK_ASSIGMENT;
bogdanm 0:9b334a45a8ff 192 m_thunk.context = (uint32_t)context;
bogdanm 0:9b334a45a8ff 193 m_thunk.instance = (uint32_t)instance;
bogdanm 0:9b334a45a8ff 194 m_thunk.callback = (uint32_t)&m_callback;
bogdanm 0:9b334a45a8ff 195 m_thunk.trampoline = (uint32_t)&trampoline;
bogdanm 0:9b334a45a8ff 196
bogdanm 0:9b334a45a8ff 197 __ISB();
bogdanm 0:9b334a45a8ff 198 __DSB();
bogdanm 0:9b334a45a8ff 199 }
bogdanm 0:9b334a45a8ff 200 };
bogdanm 0:9b334a45a8ff 201
bogdanm 0:9b334a45a8ff 202 #endif/*__CTHUNK_H__*/