diff --git a/arch/arm/src/kinetis/kinetis_start.c b/arch/arm/src/kinetis/kinetis_start.c index 21885d92682..7f209b1351b 100644 --- a/arch/arm/src/kinetis/kinetis_start.c +++ b/arch/arm/src/kinetis/kinetis_start.c @@ -54,9 +54,59 @@ #include "chip/kinetis_smc.h" #include "kinetis_userspace.h" +#ifdef CONFIG_ARCH_FPU +# include "nvic.h" +#endif + +/**************************************************************************** + * Private Function prototypes + ****************************************************************************/ + +#ifdef CONFIG_ARCH_FPU +static inline void stm32_fpuconfig(void); +#endif +#ifdef CONFIG_STACK_COLORATION +static void go_os_start(void *pv, unsigned int nbytes) + __attribute__ ((naked, no_instrument_function, noreturn)); +#endif + /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ +/* Memory Map ***************************************************************/ +/* + * 0x0000:0000 - Beginning of the internal FLASH. Address of vectors. + * Mapped as boot memory address 0x0000:0000 at reset. + * 0x07ff:ffff - End of flash region (assuming the max of 2MiB of FLASH). + * 0x1fff:0000 - Start of internal SRAM and start of .data (_sdata) + * - End of .data (_edata) and start of .bss (_sbss) + * - End of .bss (_ebss) and bottom of idle stack + * - _ebss + CONFIG_IDLETHREAD_STACKSIZE = end of idle stack, + * start of heap. NOTE that the ARM uses a decrement before + * store stack so that the correct initial value is the end of + * the stack + 4; + * 0x2002:ffff - End of internal SRAM and end of heap (a + */ + +#define IDLE_STACK ((uintptr_t)&_ebss+CONFIG_IDLETHREAD_STACKSIZE-4) +#define HEAP_BASE ((uintptr_t)&_ebss+CONFIG_IDLETHREAD_STACKSIZE) + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/* g_idle_topstack: _sbss is the start of the BSS region as defined by the + * linker script. _ebss lies at the end of the BSS region. The idle task + * stack starts at the end of BSS and is of size CONFIG_IDLETHREAD_STACKSIZE. + * The IDLE thread is the thread that the system boots on and, eventually, + * becomes the IDLE, do nothing task that runs only when there is nothing + * else to run. The heap continues from there until the end of memory. + * g_idle_topstack is a read-only variable the provides this computed + * address. + */ +#if defined(CONFIG_ARMV7M_CMNVECTOR) +const uintptr_t g_idle_topstack = HEAP_BASE; +#endif /**************************************************************************** * Private Data @@ -70,6 +120,143 @@ * Private Functions ****************************************************************************/ + +#ifdef CONFIG_ARMV7M_STACKCHECK +/* we need to get r10 set before we can allow instrumentation calls */ + +void __start(void) __attribute__ ((no_instrument_function)); +#endif + +/**************************************************************************** + * Name: stm32_fpuconfig + * + * Description: + * Configure the FPU. Relative bit settings: + * + * CPACR: Enables access to CP10 and CP11 + * CONTROL.FPCA: Determines whether the FP extension is active in the + * current context: + * FPCCR.ASPEN: Enables automatic FP state preservation, then the + * processor sets this bit to 1 on successful completion of any FP + * instruction. + * FPCCR.LSPEN: Enables lazy context save of FP state. When this is + * done, the processor reserves space on the stack for the FP state, + * but does not save that state information to the stack. + * + * Software must not change the value of the ASPEN bit or LSPEN bit while either: + * - the CPACR permits access to CP10 and CP11, that give access to the FP + * extension, or + * - the CONTROL.FPCA bit is set to 1 + * + ****************************************************************************/ + +#ifdef CONFIG_ARCH_FPU +#if defined(CONFIG_ARMV7M_CMNVECTOR) && !defined(CONFIG_ARMV7M_LAZYFPU) + +static inline void stm32_fpuconfig(void) +{ + uint32_t regval; + + /* Set CONTROL.FPCA so that we always get the extended context frame + * with the volatile FP registers stacked above the basic context. + */ + + regval = getcontrol(); + regval |= (1 << 2); + setcontrol(regval); + + /* Ensure that FPCCR.LSPEN is disabled, so that we don't have to contend + * with the lazy FP context save behaviour. Clear FPCCR.ASPEN since we + * are going to turn on CONTROL.FPCA for all contexts. + */ + + regval = getreg32(NVIC_FPCCR); + regval &= ~((1 << 31) | (1 << 30)); + putreg32(regval, NVIC_FPCCR); + + /* Enable full access to CP10 and CP11 */ + + regval = getreg32(NVIC_CPACR); + regval |= ((3 << (2*10)) | (3 << (2*11))); + putreg32(regval, NVIC_CPACR); +} + +#else + +static inline void stm32_fpuconfig(void) +{ + uint32_t regval; + + /* Clear CONTROL.FPCA so that we do not get the extended context frame + * with the volatile FP registers stacked in the saved context. + */ + + regval = getcontrol(); + regval &= ~(1 << 2); + setcontrol(regval); + + /* Ensure that FPCCR.LSPEN is disabled, so that we don't have to contend + * with the lazy FP context save behaviour. Clear FPCCR.ASPEN since we + * are going to keep CONTROL.FPCA off for all contexts. + */ + + regval = getreg32(NVIC_FPCCR); + regval &= ~((1 << 31) | (1 << 30)); + putreg32(regval, NVIC_FPCCR); + + /* Enable full access to CP10 and CP11 */ + + regval = getreg32(NVIC_CPACR); + regval |= ((3 << (2*10)) | (3 << (2*11))); + putreg32(regval, NVIC_CPACR); +} + +#endif + +#else +# define stm32_fpuconfig() +#endif + +/**************************************************************************** + * Name: go_os_start + * + * Description: + * Set the IDLE stack to the + * + ****************************************************************************/ + +#ifdef CONFIG_STACK_COLORATION +static void go_os_start(void *pv, unsigned int nbytes) +{ + /* Set the IDLE stack to the stack coloration value then jump to + * os_start(). We take extreme care here because were currently + * executing on this stack. + * + * We want to avoid sneak stack access generated by the compiler. + */ + + __asm__ __volatile__ + ( + "\tmovs r1, r1, lsr #2\n" /* R1 = nwords = nbytes >> 2 */ + "\tbeq 2f\n" /* (should not happen) */ + + "\tbic r0, r0, #3\n" /* R0 = Aligned stackptr */ + "\tmovw r2, #0xbeef\n" /* R2 = STACK_COLOR = 0xdeadbeef */ + "\tmovt r2, #0xdead\n" + + "1:\n" /* Top of the loop */ + "\tsub r1, r1, #1\n" /* R1 nwords-- */ + "\tcmp r1, #0\n" /* Check (nwords == 0) */ + "\tstr r2, [r0], #4\n" /* Save stack color word, increment stackptr */ + "\tbne 1b\n" /* Bottom of the loop */ + + "2:\n" + "\tmov r14, #0\n" /* LR = return address (none) */ + "\tb os_start\n" /* Branch to os_start */ + ); +} +#endif + /**************************************************************************** * Public Functions ****************************************************************************/ @@ -87,6 +274,12 @@ void __start(void) const uint32_t *src; uint32_t *dest; +#ifdef CONFIG_ARMV7M_STACKCHECK + /* Set the stack limit before we attempt to call any functions */ + + __asm__ volatile ("sub r10, sp, %0" : : "r" (CONFIG_IDLETHREAD_STACKSIZE - 64) : ); +#endif + /* Disable the watchdog timer */ kinetis_wddisable(); @@ -134,7 +327,7 @@ void __start(void) * can get debug output as soon as possible (This depends on clock * configuration). */ - + stm32_fpuconfig(); kinetis_lowsetup(); #ifdef USE_EARLYSERIALINIT up_earlyserialinit();