| /* |
| * Copyright (c) 2013-2014 Wind River Systems, Inc. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| /** |
| * @file |
| * @brief Full C support initialization |
| * |
| * |
| * Initialization of full C support: zero the .bss, copy the .data if XIP, |
| * call _Cstart(). |
| * |
| * Stack is available in this module, but not the global data/bss until their |
| * initialization is performed. |
| */ |
| |
| #include <kernel.h> |
| #include <zephyr/types.h> |
| #include <toolchain.h> |
| #include <linker/linker-defs.h> |
| #include <kernel_internal.h> |
| #include <arch/arm/cortex_m/cmsis.h> |
| #include <string.h> |
| |
| #ifdef CONFIG_CPU_CORTEX_M_HAS_VTOR |
| |
| #ifdef CONFIG_XIP |
| #define VECTOR_ADDRESS ((uintptr_t)_vector_start) |
| #else |
| #define VECTOR_ADDRESS CONFIG_SRAM_BASE_ADDRESS |
| #endif |
| static inline void relocate_vector_table(void) |
| { |
| SCB->VTOR = VECTOR_ADDRESS & SCB_VTOR_TBLOFF_Msk; |
| __DSB(); |
| __ISB(); |
| } |
| |
| #else |
| |
| #if defined(CONFIG_SW_VECTOR_RELAY) |
| _GENERIC_SECTION(.vt_pointer_section) void *_vector_table_pointer; |
| #endif |
| |
| #define VECTOR_ADDRESS 0 |
| void __weak relocate_vector_table(void) |
| { |
| #if defined(CONFIG_XIP) && (CONFIG_FLASH_BASE_ADDRESS != 0) || \ |
| !defined(CONFIG_XIP) && (CONFIG_SRAM_BASE_ADDRESS != 0) |
| size_t vector_size = (size_t)_vector_end - (size_t)_vector_start; |
| memcpy(VECTOR_ADDRESS, _vector_start, vector_size); |
| #elif defined(CONFIG_SW_VECTOR_RELAY) |
| _vector_table_pointer = _vector_start; |
| #endif |
| } |
| |
| #endif /* CONFIG_CPU_CORTEX_M_HAS_VTOR */ |
| |
| #ifdef CONFIG_FLOAT |
| static inline void enable_floating_point(void) |
| { |
| /* |
| * Upon reset, the Co-Processor Access Control Register is 0x00000000. |
| * Enable CP10 and CP11 coprocessors to enable floating point. |
| */ |
| SCB->CPACR |= CPACR_CP10_FULL_ACCESS | CPACR_CP11_FULL_ACCESS; |
| /* |
| * Upon reset, the FPU Context Control Register is 0xC0000000 |
| * (both Automatic and Lazy state preservation is enabled). |
| * Disable lazy state preservation so the volatile FP registers are |
| * always saved on exception. |
| */ |
| FPU->FPCCR = FPU_FPCCR_ASPEN_Msk; /* FPU_FPCCR_LSPEN = 0 */ |
| |
| /* |
| * Although automatic state preservation is enabled, the processor |
| * does not automatically save the volatile FP registers until they |
| * have first been touched. Perform a dummy move operation so that |
| * the stack frames are created as expected before any thread |
| * context switching can occur. It has to be surrounded by instruction |
| * synchronisation barriers to ensure that the whole sequence is |
| * serialized. |
| */ |
| __asm__ volatile( |
| "isb;\n\t" |
| "vmov s0, s0;\n\t" |
| "isb;\n\t" |
| ); |
| } |
| #else |
| static inline void enable_floating_point(void) |
| { |
| } |
| #endif |
| |
| extern FUNC_NORETURN void _Cstart(void); |
| /** |
| * |
| * @brief Prepare to and run C code |
| * |
| * This routine prepares for the execution of and runs C code. |
| * |
| * @return N/A |
| */ |
| |
| #ifdef CONFIG_BOOT_TIME_MEASUREMENT |
| extern u64_t __start_time_stamp; |
| #endif |
| void _PrepC(void) |
| { |
| relocate_vector_table(); |
| enable_floating_point(); |
| _bss_zero(); |
| _data_copy(); |
| #ifdef CONFIG_BOOT_TIME_MEASUREMENT |
| __start_time_stamp = 0; |
| #endif |
| _Cstart(); |
| CODE_UNREACHABLE; |
| } |