Diff: rtos/TARGET_CORTEX/mbed_boot.c

Revision:

0:38ceb79fef03

diff -r 000000000000 -r 38ceb79fef03 rtos/TARGET_CORTEX/mbed_boot.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rtos/TARGET_CORTEX/mbed_boot.c	Wed Nov 28 15:10:15 2018 +0000
@@ -0,0 +1,131 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2016 ARM Limited
+ *
+ * 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.
+ */
+
+/* mbed OS boot sequence
+ *
+ * Most of mbed supported targets use default ARM Cortex M boot approach, where the core starts executing reset vector
+ * after power up. Reset ISR is defined for each target by the vendor (basing on CMSIS template). Reset vector is
+ * responsible for low level platform init and then calling in libc (__main). Depending on compiler and version of C
+ * library, predefined function will be called which is implemented by mbed OS.
+ *
+ * There's number of functions, vendor and users can provide to setup the platform and/or inject a code to be executed
+ *  before main():
+ *      * Reset vector and SystemInit: Reset vector should do low level core and board initialization.
+ *      * mbed_sdk_init: Higher level board init and making sure the board is ready for the mbed OS.
+ *      * mbed_main: User's code to be executed before main().
+ *      * main: Standard application code.
+ *
+ * Other notes:
+ *
+ *    * In addition to the above, libc will use functions defined in mbed_boot.c: __rtos_malloc_lock/unlock,
+ *      __rtos_env_lock/unlock.
+ *
+ *    * First step after the execution is passed to mbed, software_init_hook for GCC and __rt_entry for ARMC is to
+ *      initialize heap.
+ *
+ * Memory layout notes:
+ * ====================
+ *
+ * IAR Default Memory layout notes:
+ * -Heap defined by "HEAP" region in .icf file
+ * -Interrupt stack defined by "CSTACK" region in .icf file
+ * -Value INITIAL_SP is ignored
+ *
+ * IAR Custom Memory layout notes:
+ * -There is no custom layout available for IAR - everything must be defined in
+ *      the .icf file and use the default layout
+ *
+ *
+ * GCC Default Memory layout notes:
+ * -Block of memory from symbol __end__ to define INITIAL_SP used to setup interrupt
+ *      stack and heap in the function set_stack_heap()
+ * -ISR_STACK_SIZE can be overridden to be larger or smaller
+ *
+ * GCC Custom Memory layout notes:
+ * -Heap can be explicitly placed by defining both HEAP_START and HEAP_SIZE
+ * -Interrupt stack can be explicitly placed by defining both ISR_STACK_START and ISR_STACK_SIZE
+ *
+ *
+ * ARM Memory layout
+ * -Block of memory from end of region "RW_IRAM1" to define INITIAL_SP used to setup interrupt
+ *      stack and heap in the function set_stack_heap()
+ * -ISR_STACK_SIZE can be overridden to be larger or smaller
+ *
+ * ARM Custom Memory layout notes:
+ * -Heap can be explicitly placed by defining both HEAP_START and HEAP_SIZE
+ * -Interrupt stack can be explicitly placed by defining both ISR_STACK_START and ISR_STACK_SIZE
+ *
+ */
+
+#include <stdlib.h>
+
+#include "cmsis.h"
+#include "mbed_toolchain.h"
+#include "mbed_boot.h"
+
+int main(void);
+static void mbed_cpy_nvic(void);
+
+/* Stack limits */
+unsigned char *mbed_stack_isr_start = 0;
+uint32_t mbed_stack_isr_size = 0;
+
+void mbed_init(void)
+{
+    mbed_cpy_nvic();
+    mbed_sdk_init();
+    mbed_rtos_init();
+}
+
+void mbed_start(void)
+{
+    mbed_toolchain_init();
+    mbed_main();
+    main();
+}
+
+MBED_WEAK void mbed_sdk_init(void)
+{
+    // Nothing by default
+}
+
+MBED_WEAK void software_init_hook_rtos()
+{
+    // Nothing by default
+}
+
+MBED_WEAK void mbed_main(void)
+{
+    // Nothing by default
+}
+
+static void mbed_cpy_nvic(void)
+{
+    /* If vector address in RAM is defined, copy and switch to dynamic vectors. Exceptions for M0 which doesn't have
+    VTOR register and for A9 for which CMSIS doesn't define NVIC_SetVector; in both cases target code is
+    responsible for correctly handling the vectors.
+    */
+#if !defined(__CORTEX_M0) && !defined(__CORTEX_A9)
+#ifdef NVIC_RAM_VECTOR_ADDRESS
+    uint32_t *old_vectors = (uint32_t *)SCB->VTOR;
+    uint32_t *vectors = (uint32_t*)NVIC_RAM_VECTOR_ADDRESS;
+    for (int i = 0; i < NVIC_NUM_VECTORS; i++) {
+        vectors[i] = old_vectors[i];
+    }
+    SCB->VTOR = (uint32_t)NVIC_RAM_VECTOR_ADDRESS;
+#endif /* NVIC_RAM_VECTOR_ADDRESS */
+#endif /* !defined(__CORTEX_M0) && !defined(__CORTEX_A9) */
+}