/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio. This file is part of ChibiOS/RT. ChibiOS/RT is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. ChibiOS/RT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /** * @defgroup ARMCMx ARM Cortex-Mx * @details ARM Cortex-Mx port for the GCC compiler. * @section ARMCMx_INTRO Introduction * This port supports all the cores implementing the ARMv6-M and ARMv7-M * architectures. * * @section ARMCMx_STATES_A System logical states in ARMv6-M mode * The ChibiOS/RT logical @ref system_states are mapped as follow in the ARM * Cortex-M0 port: * - Init. This state is represented by the startup code and the * initialization code before @p chSysInit() is executed. It has not a * special hardware state associated. * - Normal. This is the state the system has after executing * @p chSysInit(). In this state interrupts are enabled. The processor * is running in thread-privileged mode. * - Suspended. In this state the interrupt sources are globally * disabled. The processor is running in thread-privileged mode. In this * mode this state is not different from the Disabled state. * - Disabled. In this state the interrupt sources are globally * disabled. The processor is running in thread-privileged mode. In this * mode this state is not different from the Suspended state. * - Sleep. This state is entered with the execution of the specific * instruction @p wfi. * - S-Locked. In this state the interrupt sources are globally * disabled. The processor is running in thread-privileged mode. * - I-Locked. In this state the interrupt sources are globally * disabled. The processor is running in exception-privileged mode. * - Serving Regular Interrupt. In this state the interrupt sources are * not globally masked but only interrupts with higher priority can preempt * the current handler. The processor is running in exception-privileged * mode. * - Serving Fast Interrupt. This state is not implemented in the * ARMv6-M implementation. * - Serving Non-Maskable Interrupt. The Cortex-M3 has a specific * asynchronous NMI vector and several synchronous fault vectors that can * be considered belonging to this category. * - Halted. Implemented as an infinite loop after globally masking all * the maskable interrupt sources. The ARM state is whatever the processor * was running when @p chSysHalt() was invoked. * * @section ARMCMx_STATES_B System logical states in ARMv7-M mode * The ChibiOS/RT logical @ref system_states are mapped as follow in the ARM * Cortex-M3 port: * - Init. This state is represented by the startup code and the * initialization code before @p chSysInit() is executed. It has not a * special hardware state associated. * - Normal. This is the state the system has after executing * @p chSysInit(). In this state the ARM Cortex-M3 has the BASEPRI register * set at @p CORTEX_BASEPRI_USER level, interrupts are not masked. The * processor is running in thread-privileged mode. * - Suspended. In this state the interrupt sources are not globally * masked but the BASEPRI register is set to @p CORTEX_BASEPRI_KERNEL thus * masking any interrupt source with lower or equal priority. The processor * is running in thread-privileged mode. * - Disabled. Interrupt sources are globally masked. The processor * is running in thread-privileged mode. * - Sleep. This state is entered with the execution of the specific * instruction @p wfi. * - S-Locked. In this state the interrupt sources are not globally * masked but the BASEPRI register is set to @p CORTEX_BASEPRI_KERNEL thus * masking any interrupt source with lower or equal priority. The processor * is running in thread-privileged mode. * - I-Locked. In this state the interrupt sources are not globally * masked but the BASEPRI register is set to @p CORTEX_BASEPRI_KERNEL thus * masking any interrupt source with lower or equal priority. The processor * is running in exception-privileged mode. * - Serving Regular Interrupt. In this state the interrupt sources are * not globally masked but only interrupts with higher priority can preempt * the current handler. The processor is running in exception-privileged * mode. * - Serving Fast Interrupt. It is basically the same of the SRI state * but it is not possible to switch to the I-Locked state because fast * interrupts can preempt the kernel critical zone. * - Serving Non-Maskable Interrupt. The Cortex-M3 has a specific * asynchronous NMI vector and several synchronous fault vectors that can * be considered belonging to this category. * - Halted. Implemented as an infinite loop after globally masking all * the maskable interrupt sources. The ARM state is whatever the processor * was running when @p chSysHalt() was invoked. * . * @section ARMCMx_NOTES ARM Cortex-Mx/GCC port notes * The ARM Cortex-Mx port is organized as follow: * - The @p main() function is invoked in thread-privileged mode. * - Each thread has a private process stack, the system has a single main * stack where all the interrupts and exceptions are processed. * - The threads are started in thread-privileged mode. * - Interrupt nesting and the other advanced core/NVIC features are supported. * - When using an STM32 one of the following macros must be defined on the * compiler command line or in a file named board.h: * - @p STM32F10X_LD * - @p STM32F10X_MD * - @p STM32F10X_HD * - @p STM32F10X_CL * . * This is required in order to include a vectors table with the correct * length for the STM32 model, see the file * ./os/ports/GCC/ARMCMx/STM32F10x/vectors.s. * - The Cortex-Mx port is perfectly generic, support for more devices can be * easily added by adding a subdirectory under ./os/ports/GCC/ARMCMx * and giving it the name of the new device, then copy the files from another * device into the new directory and customize them for the new device. * . * @ingroup gcc */ /** * @defgroup ARMCMx_CONF Configuration Options * @details ARM Cortex-Mx Configuration Options. The ARMCMx port allows some * architecture-specific configurations settings that can be overridden * by redefining them in @p chconf.h. Usually there is no need to change * the default values. * - @p INT_REQUIRED_STACK, this value represent the amount of stack space used * by an interrupt handler between the @p extctx and @p intctx * structures. * - @p IDLE_THREAD_STACK_SIZE, stack area size to be assigned to the IDLE * thread. Usually there is no need to change this value unless inserting * code in the IDLE thread using the @p IDLE_LOOP_HOOK hook macro. * - @p CORTEX_BASEPRI_KERNEL, this is the @p BASEPRI value for the kernel lock * code. Code running at higher priority levels must not invoke any OS API. * This setting is specific to the ARMv7-M architecture. * - @p CORTEX_PRIORITY_SYSTICK, priority of the SYSTICK handler. * - @p CORTEX_PRIORITY_SVCALL, priority of the SVCALL handler. * - @p CORTEX_PRIORITY_PENDSV, priority of the PENDSV handler. * - @p CORTEX_ENABLE_WFI_IDLE, if set to @p TRUE enables the use of the * @p wfi instruction from within the idle loop. This option is * defaulted to FALSE because it can create problems with some debuggers. * Setting this option to TRUE reduces the system power requirements. * . * @ingroup ARMCMx */ /** * @defgroup ARMCMx_CORE Core Port Implementation * @details ARM Cortex-Mx specific port code, structures and macros. * * @ingroup ARMCMx */ /** * @defgroup ARMCMx_V6M_CORE ARMv6-M Specific Implementation * @details ARMv6-M specific port code, structures and macros. * * @ingroup ARMCMx_CORE */ /** * @defgroup ARMCMx_V7M_CORE ARMv7-M Specific Implementation * @details ARMv7-M specific port code, structures and macros. * * @ingroup ARMCMx_CORE */ /** * @defgroup ARMCMx_STARTUP Startup Support * @details ChibiOS/RT provides its own generic startup file for the ARM * Cortex-Mx port. * Of course it is not mandatory to use it but care should be taken about the * startup phase details. * * @section ARMCMx_STARTUP_1 Startup Process * The startup process, as implemented, is the following: * -# Interrupts are masked globally. * -# The two stacks are initialized by assigning them the sizes defined in the * linker script (usually named @p ch.ld). Stack areas are allocated from * the highest RAM location downward. * -# An early initialization routine @p hwinit0 is invoked, if the symbol is * not defined then an empty default routine is executed (weak symbol). * -# DATA and BSS segments are initialized. * -# The CPU state is switched to Privileged and the PSP stack is used. * -# A late initialization routine @p hwinit1 is invoked, if the symbol not * defined then an empty default routine is executed (weak symbol).
* This late initialization function is also the proper place for a * @a bootloader, if your application requires one. * -# The @p main() function is invoked with the parameters @p argc and @p argv * set to zero. * -# Should the @p main() function return a branch is performed to the weak * symbol MainExitHandler. The default code is an endless empty loop. * . * @section ARMCMx_STARTUP_2 Expected linker symbols * The startup code starts at the symbol @p ResetHandler and expects the * following symbols to be defined in the linker script: * - @p __ram_end__ RAM end location +1. * - @p __main_stack_size__ Exception stack size. * - @p __process_stack_size__ Process stack size. This is the stack area used * by the @p main() function. * - @p _textdata address of the data segment source read only data. * - @p _data data segment start location. * - @p _edata data segment end location +1. * - @p _bss_start BSS start location. * - @p _bss_end BSS end location +1. * . * @ingroup ARMCMx */ /** * @defgroup ARMCMx_NVIC NVIC Support * @details ARM Cortex-Mx NVIC support. * * @ingroup ARMCMx */ /** * @defgroup ARMCMx_SPECIFIC Specific Implementations * @details Platform-specific port code. * * @ingroup ARMCMx */