From 180107e971e1cc83570c38fe73d7077bd570ab21 Mon Sep 17 00:00:00 2001 From: Christian Mauderer Date: Mon, 30 Jan 2017 11:33:31 +0100 Subject: bsps/arm: Fix Cortex-M DWT CPU counter. It is necessary to enable the DWT using a special initialization sequence before the CYCCNT can be enabled. See for example the RESET_CYCLE_COUNTER in libbsp/arm/atsam/utils/utility.h. Note that this problem only occurs if no debugger is connected. A debugger most likely already enables the necessary module. --- cpukit/score/cpu/arm/rtems/score/armv7m.h | 46 ++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) (limited to 'cpukit/score') diff --git a/cpukit/score/cpu/arm/rtems/score/armv7m.h b/cpukit/score/cpu/arm/rtems/score/armv7m.h index 0a69363c7f..a6cc8a34ac 100644 --- a/cpukit/score/cpu/arm/rtems/score/armv7m.h +++ b/cpukit/score/cpu/arm/rtems/score/armv7m.h @@ -93,7 +93,7 @@ typedef struct { uint32_t foldcnt; uint32_t pcsr; ARMV7M_DWT_comparator comparator[249]; - uint32_t reserved_e0001fb0[1]; +#define ARMV7M_DWT_LAR_UNLOCK_MAGIC 0xc5acce55U uint32_t lar; uint32_t lsr; } ARMV7M_DWT; @@ -347,6 +347,26 @@ typedef struct { 0 \ } +typedef struct { + uint32_t dhcsr; + uint32_t dcrsr; + uint32_t dcrdr; +#define ARMV7M_DEBUG_DEMCR_VC_CORERESET (1U << 0) +#define ARMV7M_DEBUG_DEMCR_VC_MMERR (1U << 4) +#define ARMV7M_DEBUG_DEMCR_VC_NOCPERR (1U << 5) +#define ARMV7M_DEBUG_DEMCR_VC_CHKERR (1U << 6) +#define ARMV7M_DEBUG_DEMCR_VC_STATERR (1U << 7) +#define ARMV7M_DEBUG_DEMCR_VC_BUSERR (1U << 8) +#define ARMV7M_DEBUG_DEMCR_VC_INTERR (1U << 9) +#define ARMV7M_DEBUG_DEMCR_VC_HARDERR (1U << 10) +#define ARMV7M_DEBUG_DEMCR_MON_EN (1U << 16) +#define ARMV7M_DEBUG_DEMCR_MON_PEND (1U << 17) +#define ARMV7M_DEBUG_DEMCR_MON_STEP (1U << 18) +#define ARMV7M_DEBUG_DEMCR_MON_REQ (1U << 19) +#define ARMV7M_DEBUG_DEMCR_TRCENA (1U << 24) + uint32_t demcr; +} ARMV7M_DEBUG; + #define ARMV7M_DWT_BASE 0xe0001000 #define ARMV7M_SCS_BASE 0xe000e000 #define ARMV7M_ICTAC_BASE (ARMV7M_SCS_BASE + 0x0) @@ -354,6 +374,7 @@ typedef struct { #define ARMV7M_NVIC_BASE (ARMV7M_SCS_BASE + 0x100) #define ARMV7M_SCB_BASE (ARMV7M_SCS_BASE + 0xd00) #define ARMV7M_MPU_BASE (ARMV7M_SCS_BASE + 0xd90) +#define ARMV7M_DEBUG_BASE (ARMV7M_SCS_BASE + 0xdf0) #define _ARMV7M_DWT \ ((volatile ARMV7M_DWT *) ARMV7M_DWT_BASE) @@ -367,6 +388,8 @@ typedef struct { ((volatile ARMV7M_NVIC *) ARMV7M_NVIC_BASE) #define _ARMV7M_MPU \ ((volatile ARMV7M_MPU *) ARMV7M_MPU_BASE) +#define _ARMV7M_DEBUG \ + ((volatile ARMV7M_DEBUG *) ARMV7M_DEBUG_BASE) #define ARMV7M_VECTOR_MSP 0 #define ARMV7M_VECTOR_RESET 1 @@ -535,6 +558,27 @@ static inline int _ARMV7M_NVIC_Get_priority( int irq ) return _ARMV7M_NVIC->ipr [irq]; } +static inline bool _ARMV7M_DWT_Enable_CYCCNT( void ) +{ + uint32_t demcr; + uint32_t dwt_ctrl; + + demcr = _ARMV7M_DEBUG->demcr; + _ARMV7M_DEBUG->demcr = demcr | ARMV7M_DEBUG_DEMCR_TRCENA; + _ARM_Data_synchronization_barrier(); + + dwt_ctrl = _ARMV7M_DWT->ctrl; + if ((dwt_ctrl & ARMV7M_DWT_CTRL_NOCYCCNT) == 0) { + _ARMV7M_DWT->lar = ARMV7M_DWT_LAR_UNLOCK_MAGIC; + _ARM_Data_synchronization_barrier(); + _ARMV7M_DWT->ctrl = dwt_ctrl | ARMV7M_DWT_CTRL_CYCCNTENA; + return true; + } else { + _ARMV7M_DEBUG->demcr = demcr; + return false; + } +} + int _ARMV7M_Get_exception_priority( int vector ); void _ARMV7M_Set_exception_priority( int vector, int priority ); -- cgit v1.2.3