From 169e5bf1862ab52c4ba28a26f15124293d2bf443 Mon Sep 17 00:00:00 2001 From: Adrian Negreanu Date: Fri, 20 Nov 2020 18:53:51 +0200 Subject: [PATCH] armv7m_trace_itm_config: wait for ITMBusy to be cleared pg315 of CoreSight Components: It is recommended that the ITMEn bit is cleared and waits for the ITMBusy bit to be cleared, before changing any fields in the Control Register, otherwise the behavior can be unpredictable. Change-Id: Ie9a2b842825c98ee5edc9a35776320c668047769 Signed-off-by: Adrian Negreanu Reviewed-on: http://openocd.zylin.com/6043 Tested-by: jenkins Reviewed-by: Antonio Borneo --- src/target/armv7m_trace.c | 28 ++++++++++++++++++++++++++++ src/target/cortex_m.h | 2 ++ 2 files changed, 30 insertions(+) diff --git a/src/target/armv7m_trace.c b/src/target/armv7m_trace.c index 10f14221d..32b48a7c5 100644 --- a/src/target/armv7m_trace.c +++ b/src/target/armv7m_trace.c @@ -24,6 +24,7 @@ #include #include #include +#include #define TRACE_BUF_SIZE 4096 @@ -162,6 +163,33 @@ int armv7m_trace_itm_config(struct target *target) if (retval != ERROR_OK) return retval; + /* pg315 of CoreSight Components + * It is recommended that the ITMEn bit is cleared and waits for the + * ITMBusy bit to be cleared, before changing any fields in the + * Control Register, otherwise the behavior can be unpredictable. + */ + uint32_t itm_tcr; + retval = target_read_u32(target, ITM_TCR, &itm_tcr); + if (retval != ERROR_OK) + return retval; + retval = target_write_u32(target, + ITM_TCR, + itm_tcr & ~ITM_TCR_ITMENA_BIT + ); + if (retval != ERROR_OK) + return retval; + + int64_t then = timeval_ms() + 1000; + do { + retval = target_read_u32(target, ITM_TCR, &itm_tcr); + if (retval != ERROR_OK) + return retval; + if (timeval_ms() > then) { + LOG_ERROR("timeout waiting for ITM_TCR_BUSY_BIT"); + return ERROR_FAIL; + } + } while (itm_tcr & ITM_TCR_BUSY_BIT); + /* Enable ITM, TXENA, set TraceBusID and other parameters */ retval = target_write_u32(target, ITM_TCR, (1 << 0) | (1 << 3) | (trace_config->itm_diff_timestamps << 1) | diff --git a/src/target/cortex_m.h b/src/target/cortex_m.h index b470fbd70..1e2197b1a 100644 --- a/src/target/cortex_m.h +++ b/src/target/cortex_m.h @@ -35,6 +35,8 @@ #define ITM_TER0 0xE0000E00 #define ITM_TPR 0xE0000E40 #define ITM_TCR 0xE0000E80 +#define ITM_TCR_ITMENA_BIT BIT(0) +#define ITM_TCR_BUSY_BIT BIT(23) #define ITM_LAR 0xE0000FB0 #define ITM_LAR_KEY 0xC5ACCE55 -- 2.47.2