From 442e2506b1d535c9420a29066f5d9c8fb11de35a Mon Sep 17 00:00:00 2001 From: Matthias Welwarsky Date: Thu, 29 Oct 2015 13:09:29 +0100 Subject: [PATCH] cortex_a: force cache and tlb bypass when cpu is in debug state for minimal impact on the hardware state, force all memory accesses to bypass the caches and tlbs. This may actually be the default, but ARM recommends in DDI0406C to set proper default values on debug init. Change-Id: If5ac097b6ee725c047b1e86c2f90eabe16b98c7b Signed-off-by: Matthias Welwarsky Reviewed-on: http://openocd.zylin.com/3079 Reviewed-by: Paul Fertser Tested-by: jenkins --- src/target/armv7a.h | 1 + src/target/cortex_a.c | 12 ++++++++++++ 2 files changed, 13 insertions(+) diff --git a/src/target/armv7a.h b/src/target/armv7a.h index 3f2bdd34..8d7bece1 100644 --- a/src/target/armv7a.h +++ b/src/target/armv7a.h @@ -172,6 +172,7 @@ target_to_armv7a(struct target *target) /* See ARMv7a arch spec section C10.7 */ #define CPUDBG_DSCCR 0x028 +#define CPUDBG_DSMCR 0x02C /* See ARMv7a arch spec section C10.8 */ #define CPUDBG_AUTHSTATUS 0xFB8 diff --git a/src/target/cortex_a.c b/src/target/cortex_a.c index 5268cf21..61a5df38 100644 --- a/src/target/cortex_a.c +++ b/src/target/cortex_a.c @@ -243,6 +243,18 @@ static int cortex_a_init_debug_access(struct target *target) if (retval != ERROR_OK) return retval; + /* Disable cacheline fills and force cache write-through in debug state */ + retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap, + armv7a->debug_base + CPUDBG_DSCCR, 0); + if (retval != ERROR_OK) + return retval; + + /* Disable TLB lookup and refill/eviction in debug state */ + retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap, + armv7a->debug_base + CPUDBG_DSMCR, 0); + if (retval != ERROR_OK) + return retval; + /* Enabling of instruction execution in debug mode is done in debug_entry code */ /* Resync breakpoint registers */ -- 2.39.2