| /* |
| * Copyright (c) 2013-2014 Wind River Systems, Inc. |
| * |
| * 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. |
| */ |
| |
| /** |
| * @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 <nanokernel.h> |
| #include <stdint.h> |
| #include <toolchain.h> |
| #include <linker-defs.h> |
| #include <nano_internal.h> |
| |
| #ifdef CONFIG_XIP |
| static inline void relocate_vector_table(void) { /* do nothing */ } |
| #else |
| static inline void relocate_vector_table(void) |
| { |
| /* vector table is already in SRAM, just point to it */ |
| _scs_relocate_vector_table((void *)CONFIG_SRAM_BASE_ADDRESS); |
| } |
| #endif |
| |
| #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. |
| */ |
| __scs.cpacr.val = (_SCS_CPACR_CP10_FULL_ACCESS | |
| _SCS_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. |
| */ |
| __scs.fpu.ccr.val = (_SCS_FPU_CCR_ASPEN_ENABLE | |
| _SCS_FPU_CCR_LSPEN_DISABLE); |
| |
| /* |
| * 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 task or fiber |
| * context switching can occur. |
| */ |
| __asm__ volatile( |
| "vmov s0, s0;\n\t" |
| "dsb;\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 |
| */ |
| |
| void _PrepC(void) |
| { |
| relocate_vector_table(); |
| enable_floating_point(); |
| _bss_zero(); |
| _data_copy(); |
| _Cstart(); |
| CODE_UNREACHABLE; |
| } |