From 1fb736f6c5a69f743dd90e68045f7b4e6a0f8c78 Mon Sep 17 00:00:00 2001 From: Chengyu Zheng Date: Wed, 14 Dec 2016 12:18:10 +0100 Subject: target/cortex_a: add support for watchpoints The current implementation of OpenOCD does not support watchpoints for cortex_a architecture. So, I replaced the add_watchpoint and remove_watchpoint with the specific implementation for the cortex a and using the breakpoint implementation and the arm documentation [1] as reference. In particular, I have made the following changes: * added the following functions - cortex_a_add_watchpoint This wrapper function check whether there are any watchpoint available on the target device by calling cortex_a_set_watchpoint. - cortex_a_set_watchpoint This function is responsible for settings the watchpoint register pair. In particular, it sets the WVR and the WCR registers with the cortex_a_dap command. - cortex_a_remove_watchpoint This wrapper function the selected watchpoint on the target device by calling cortex_a_unset_watchpoint. - cortex_a_unset_watchpoint This function sets both the WVR and the WCR registers to zero, thus unsetting the watchpoint. [1] http://infocenter.arm.com/help/topic/com.arm.doc.ddi0464f/BCGDHIEJ.html Change-Id: I86611dab474cb84836662af572b17636dc68e282 Signed-off-by: Chengyu Zheng Reviewed-on: http://openocd.zylin.com/3913 Reviewed-by: Antonio Borneo Reviewed-by: Matthias Welwarsky Reviewed-by: Marc Schink Tested-by: jenkins --- src/target/arm_dpm.c | 8 ++- src/target/armv7a.c | 2 - src/target/cortex_a.c | 190 ++++++++++++++++++++++++++++++++++++++++++++++++-- src/target/cortex_a.h | 10 +++ 4 files changed, 201 insertions(+), 9 deletions(-) diff --git a/src/target/arm_dpm.c b/src/target/arm_dpm.c index e172fad..058f0df 100644 --- a/src/target/arm_dpm.c +++ b/src/target/arm_dpm.c @@ -1088,9 +1088,11 @@ int arm_dpm_setup(struct arm_dpm *dpm) target->type->remove_breakpoint = dpm_remove_breakpoint; } - /* watchpoint setup */ - target->type->add_watchpoint = dpm_add_watchpoint; - target->type->remove_watchpoint = dpm_remove_watchpoint; + /* watchpoint setup -- optional until it works everywhere */ + if (!target->type->add_watchpoint) { + target->type->add_watchpoint = dpm_add_watchpoint; + target->type->remove_watchpoint = dpm_remove_watchpoint; + } /* FIXME add vector catch support */ diff --git a/src/target/armv7a.c b/src/target/armv7a.c index 5c9f308..5f7b008 100644 --- a/src/target/armv7a.c +++ b/src/target/armv7a.c @@ -570,8 +570,6 @@ int armv7a_arch_state(struct target *target) if (arm->core_mode == ARM_MODE_ABT) armv7a_show_fault_registers(target); - if (target->debug_reason == DBG_REASON_WATCHPOINT) - LOG_USER("Watchpoint triggered at PC " TARGET_ADDR_FMT, armv7a->dpm.wp_addr); return ERROR_OK; } diff --git a/src/target/cortex_a.c b/src/target/cortex_a.c index 5018a91..9e8248a 100644 --- a/src/target/cortex_a.c +++ b/src/target/cortex_a.c @@ -23,6 +23,9 @@ * Copyright (C) 2013 Kamal Dasu * * kdasu.kdev@gmail.com * * * + * Copyright (C) 2016 Chengyu Zheng * + * chengyu.zheng@polimi.it : watchpoint support * + * * * This program 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 2 of the License, or * @@ -80,6 +83,16 @@ static int cortex_a_virt2phys(struct target *target, static int cortex_a_read_cpu_memory(struct target *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer); +static unsigned int ilog2(unsigned int x) +{ + unsigned int y = 0; + x /= 2; + while (x) { + ++y; + x /= 2; + } + return y; +} /* restore cp15_control_reg at resume */ static int cortex_a_restore_cp15_control_reg(struct target *target) @@ -1658,6 +1671,161 @@ static int cortex_a_remove_breakpoint(struct target *target, struct breakpoint * return ERROR_OK; } +/** + * Sets a watchpoint for an Cortex-A target in one of the watchpoint units. It is + * considered a bug to call this function when there are no available watchpoint + * units. + * + * @param target Pointer to an Cortex-A target to set a watchpoint on + * @param watchpoint Pointer to the watchpoint to be set + * @return Error status if watchpoint set fails or the result of executing the + * JTAG queue + */ +static int cortex_a_set_watchpoint(struct target *target, struct watchpoint *watchpoint) +{ + int retval = ERROR_OK; + int wrp_i = 0; + uint32_t control; + uint8_t address_mask = ilog2(watchpoint->length); + uint8_t byte_address_select = 0xFF; + uint8_t load_store_access_control = 0x3; + struct cortex_a_common *cortex_a = target_to_cortex_a(target); + struct armv7a_common *armv7a = &cortex_a->armv7a_common; + struct cortex_a_wrp *wrp_list = cortex_a->wrp_list; + + if (watchpoint->set) { + LOG_WARNING("watchpoint already set"); + return retval; + } + + /* check available context WRPs */ + while (wrp_list[wrp_i].used && (wrp_i < cortex_a->wrp_num)) + wrp_i++; + + if (wrp_i >= cortex_a->wrp_num) { + LOG_ERROR("ERROR Can not find free Watchpoint Register Pair"); + return ERROR_FAIL; + } + + if (address_mask == 0x1 || address_mask == 0x2) { + LOG_WARNING("length must be a power of 2 and different than 2 and 4"); + return ERROR_FAIL; + } + + watchpoint->set = wrp_i + 1; + control = (address_mask << 24) | + (byte_address_select << 5) | + (load_store_access_control << 3) | + (0x3 << 1) | 1; + wrp_list[wrp_i].used = 1; + wrp_list[wrp_i].value = (watchpoint->address & 0xFFFFFFFC); + wrp_list[wrp_i].control = control; + + retval = cortex_a_dap_write_memap_register_u32(target, armv7a->debug_base + + CPUDBG_WVR_BASE + 4 * wrp_list[wrp_i].WRPn, + wrp_list[wrp_i].value); + if (retval != ERROR_OK) + return retval; + + retval = cortex_a_dap_write_memap_register_u32(target, armv7a->debug_base + + CPUDBG_WCR_BASE + 4 * wrp_list[wrp_i].WRPn, + wrp_list[wrp_i].control); + if (retval != ERROR_OK) + return retval; + + LOG_DEBUG("wp %i control 0x%0" PRIx32 " value 0x%0" PRIx32, wrp_i, + wrp_list[wrp_i].control, + wrp_list[wrp_i].value); + + return ERROR_OK; +} + +/** + * Unset an existing watchpoint and clear the used watchpoint unit. + * + * @param target Pointer to the target to have the watchpoint removed + * @param watchpoint Pointer to the watchpoint to be removed + * @return Error status while trying to unset the watchpoint or the result of + * executing the JTAG queue + */ +static int cortex_a_unset_watchpoint(struct target *target, struct watchpoint *watchpoint) +{ + int retval; + struct cortex_a_common *cortex_a = target_to_cortex_a(target); + struct armv7a_common *armv7a = &cortex_a->armv7a_common; + struct cortex_a_wrp *wrp_list = cortex_a->wrp_list; + + if (!watchpoint->set) { + LOG_WARNING("watchpoint not set"); + return ERROR_OK; + } + + int wrp_i = watchpoint->set - 1; + if (wrp_i < 0 || wrp_i >= cortex_a->wrp_num) { + LOG_DEBUG("Invalid WRP number in watchpoint"); + return ERROR_OK; + } + LOG_DEBUG("wrp %i control 0x%0" PRIx32 " value 0x%0" PRIx32, wrp_i, + wrp_list[wrp_i].control, wrp_list[wrp_i].value); + wrp_list[wrp_i].used = 0; + wrp_list[wrp_i].value = 0; + wrp_list[wrp_i].control = 0; + retval = cortex_a_dap_write_memap_register_u32(target, armv7a->debug_base + + CPUDBG_WCR_BASE + 4 * wrp_list[wrp_i].WRPn, + wrp_list[wrp_i].control); + if (retval != ERROR_OK) + return retval; + retval = cortex_a_dap_write_memap_register_u32(target, armv7a->debug_base + + CPUDBG_WVR_BASE + 4 * wrp_list[wrp_i].WRPn, + wrp_list[wrp_i].value); + if (retval != ERROR_OK) + return retval; + watchpoint->set = 0; + + return ERROR_OK; +} + +/** + * Add a watchpoint to an Cortex-A target. If there are no watchpoint units + * available, an error response is returned. + * + * @param target Pointer to the Cortex-A target to add a watchpoint to + * @param watchpoint Pointer to the watchpoint to be added + * @return Error status while trying to add the watchpoint + */ +static int cortex_a_add_watchpoint(struct target *target, struct watchpoint *watchpoint) +{ + struct cortex_a_common *cortex_a = target_to_cortex_a(target); + + if (cortex_a->wrp_num_available < 1) { + LOG_INFO("no hardware watchpoint available"); + return ERROR_TARGET_RESOURCE_NOT_AVAILABLE; + } + + cortex_a->wrp_num_available--; + return cortex_a_set_watchpoint(target, watchpoint); +} + +/** + * Remove a watchpoint from an Cortex-A target. The watchpoint will be unset and + * the used watchpoint unit will be reopened. + * + * @param target Pointer to the target to remove a watchpoint from + * @param watchpoint Pointer to the watchpoint to be removed + * @return Result of trying to unset the watchpoint + */ +static int cortex_a_remove_watchpoint(struct target *target, struct watchpoint *watchpoint) +{ + struct cortex_a_common *cortex_a = target_to_cortex_a(target); + + if (watchpoint->set) { + cortex_a->wrp_num_available++; + cortex_a_unset_watchpoint(target, watchpoint); + } + return ERROR_OK; +} + + /* * Cortex-A Reset functions */ @@ -2837,6 +3005,20 @@ static int cortex_a_examine_first(struct target *target) LOG_DEBUG("Configured %i hw breakpoints", cortex_a->brp_num); + /* Setup Watchpoint Register Pairs */ + cortex_a->wrp_num = ((didr >> 28) & 0x0F) + 1; + cortex_a->wrp_num_available = cortex_a->brp_num; + free(cortex_a->wrp_list); + cortex_a->wrp_list = calloc(cortex_a->wrp_num, sizeof(struct cortex_a_wrp)); + for (i = 0; i < cortex_a->wrp_num; i++) { + cortex_a->wrp_list[i].used = 0; + cortex_a->wrp_list[i].value = 0; + cortex_a->wrp_list[i].control = 0; + cortex_a->wrp_list[i].WRPn = i; + } + + LOG_DEBUG("Configured %i hw watchpoints", cortex_a->wrp_num); + /* select debug_ap as default */ swjdp->apsel = armv7a->debug_ap->ap_num; @@ -3173,8 +3355,8 @@ struct target_type cortexa_target = { .add_context_breakpoint = cortex_a_add_context_breakpoint, .add_hybrid_breakpoint = cortex_a_add_hybrid_breakpoint, .remove_breakpoint = cortex_a_remove_breakpoint, - .add_watchpoint = NULL, - .remove_watchpoint = NULL, + .add_watchpoint = cortex_a_add_watchpoint, + .remove_watchpoint = cortex_a_remove_watchpoint, .commands = cortex_a_command_handlers, .target_create = cortex_a_target_create, @@ -3250,8 +3432,8 @@ struct target_type cortexr4_target = { .add_context_breakpoint = cortex_a_add_context_breakpoint, .add_hybrid_breakpoint = cortex_a_add_hybrid_breakpoint, .remove_breakpoint = cortex_a_remove_breakpoint, - .add_watchpoint = NULL, - .remove_watchpoint = NULL, + .add_watchpoint = cortex_a_add_watchpoint, + .remove_watchpoint = cortex_a_remove_watchpoint, .commands = cortex_r4_command_handlers, .target_create = cortex_r4_target_create, diff --git a/src/target/cortex_a.h b/src/target/cortex_a.h index 197a599..dd135ec 100644 --- a/src/target/cortex_a.h +++ b/src/target/cortex_a.h @@ -71,6 +71,13 @@ struct cortex_a_brp { uint8_t BRPn; }; +struct cortex_a_wrp { + int used; + uint32_t value; + uint32_t control; + uint8_t WRPn; +}; + struct cortex_a_common { int common_magic; @@ -92,6 +99,9 @@ struct cortex_a_common { int brp_num; int brp_num_available; struct cortex_a_brp *brp_list; + int wrp_num; + int wrp_num_available; + struct cortex_a_wrp *wrp_list; uint32_t cpuid; uint32_t didr; -- cgit v1.1