| // Copyright 2020 The Pigweed Authors |
| // |
| // 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 |
| // |
| // https://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. |
| |
| #include "pw_boot/boot.h" |
| |
| #include "pw_boot_cortex_m/boot.h" |
| #include "pw_malloc/malloc.h" |
| #include "pw_preprocessor/compiler.h" |
| #include "pw_sys_io_baremetal_stm32f429/init.h" |
| |
| // Note that constexpr is used inside of this function instead of using a static |
| // constexpr or declaring it outside of this function in an anonymous namespace, |
| // because constexpr makes it available for the compiler to evaluate during |
| // compile time but does NOT require it to be evaluated at compile time and we |
| // have to be incredibly careful that this does not end up in the .data section. |
| void pw_boot_PreStaticMemoryInit() { |
| // TODO(pwbug/17): Optionally enable Replace when Pigweed config system is |
| // added. |
| #if PW_ARMV7M_ENABLE_FPU |
| // Enable FPU if built using hardware FPU instructions. |
| // CPCAR mask that enables FPU. (ARMv7-M Section B3.2.20) |
| constexpr uint32_t kFpuEnableMask = (0xFu << 20); |
| |
| // Memory mapped register to enable FPU. (ARMv7-M Section B3.2.2, Table B3-4) |
| volatile uint32_t& arm_v7m_cpacr = |
| *reinterpret_cast<volatile uint32_t*>(0xE000ED88u); |
| arm_v7m_cpacr |= kFpuEnableMask; |
| |
| // Ensure the FPU configuration is committed and enabled before continuing and |
| // potentially executing any FPU instructions, however rare that may be during |
| // startup. |
| asm volatile( |
| " dsb \n" |
| " isb \n" |
| // clang-format off |
| : /*output=*/ |
| : /*input=*/ |
| : /*clobbers=*/"memory" |
| // clang-format on |
| ); |
| #endif // PW_ARMV7M_ENABLE_FPU |
| } |
| |
| void pw_boot_PreStaticConstructorInit() { |
| #if PW_MALLOC_ACTIVE |
| pw_MallocInit(&pw_boot_heap_low_addr, &pw_boot_heap_high_addr); |
| #endif // PW_MALLOC_ACTIVE |
| } |
| |
| void pw_boot_PreMainInit() { pw_sys_io_stm32f429_Init(); } |
| |
| PW_NO_RETURN void pw_boot_PostMain() { |
| // In case main() returns, just sit here until the device is reset. |
| while (true) { |
| } |
| PW_UNREACHABLE; |
| } |