fix(stm32mp1): do not reopen debug features

On closed chips, it is not allowed to open debug. The BSEC debug
register can not be rewritten.
On open chips, the debug is already open, no need to rewrite this
register. This part of code is just removed.
An INFO message is displayed if debug is disabled.
The freeze of the watchdog during debug is also removed.
In case of debug, this must be managed by the software that enables
the debugger.

Change-Id: I19fbd3c487bb1018db30fd599cfa94fe5090899f
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>

diff --git a/plat/st/stm32mp1/bl2_plat_setup.c b/plat/st/stm32mp1/bl2_plat_setup.c
index 3a79cfd81186ca6062a91e6376c093db1af44666..b897e0d78939c22d773e0f40bcd68fe9bb0eb1e2 100644 (file)
--- a/plat/st/stm32mp1/bl2_plat_setup.c
+++ b/plat/st/stm32mp1/bl2_plat_setup.c
@@ -159,7 +159,6 @@ void bl2_platform_setup(void)
 
 void bl2_el3_plat_arch_setup(void)
 {
-       int32_t result;
        const char *board_model;
        boot_api_context_t *boot_context =
                (boot_api_context_t *)stm32mp_get_boot_ctx_address();
@@ -293,11 +292,6 @@ skip_console_init:
 
        stm32_iwdg_refresh();
 
-       result = stm32mp1_dbgmcu_freeze_iwdg2();
-       if (result != 0) {
-               INFO("IWDG2 freeze error : %i\n", result);
-       }
-
        stm32mp1_auth_ops.check_key = boot_context->bootrom_ecdsa_check_key;
        stm32mp1_auth_ops.verify_signature =
                boot_context->bootrom_ecdsa_verify_signature;

diff --git a/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h b/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h
index 498a4f210c7cc576d6c834189f6f4c8257a7b120..3663bce67f830ff2b3b15aed7935bd9603f3012c 100644 (file)
--- a/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h
+++ b/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2019, STMicroelectronics - All Rights Reserved
+ * Copyright (c) 2015-2021, STMicroelectronics - All Rights Reserved
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -13,11 +13,4 @@
 int stm32mp1_dbgmcu_get_chip_version(uint32_t *chip_version);
 int stm32mp1_dbgmcu_get_chip_dev_id(uint32_t *chip_dev_id);
 
-/*
- * Freeze watchdog when a debugger is attached, if the security configuration
- * allows it.
- * Return 0 on success, a negative error value otherwise.
- */
-int stm32mp1_dbgmcu_freeze_iwdg2(void);
-
 #endif /* STM32MP1_DBGMCU_H */

diff --git a/plat/st/stm32mp1/stm32mp1_dbgmcu.c b/plat/st/stm32mp1/stm32mp1_dbgmcu.c
index 90323ac6132311da79c7d61fffa7c146f1a2d273..1826783fb2c7a77b6795ca60259273d472ab5247 100644 (file)
--- a/plat/st/stm32mp1/stm32mp1_dbgmcu.c
+++ b/plat/st/stm32mp1/stm32mp1_dbgmcu.c
@@ -18,28 +18,16 @@
 #include <stm32mp1_dbgmcu.h>
 
 #define DBGMCU_IDC             U(0x00)
-#define DBGMCU_APB4FZ1         U(0x2C)
 
 #define DBGMCU_IDC_DEV_ID_MASK GENMASK(11, 0)
 #define DBGMCU_IDC_REV_ID_MASK GENMASK(31, 16)
 #define DBGMCU_IDC_REV_ID_SHIFT        16
 
-#define DBGMCU_APB4FZ1_IWDG2   BIT(2)
-
 static int stm32mp1_dbgmcu_init(void)
 {
-       uint32_t dbg_conf;
-
-       dbg_conf = bsec_read_debug_conf();
-
-       if ((dbg_conf & BSEC_DBGSWGEN) == 0U) {
-               uint32_t result = bsec_write_debug_conf(dbg_conf |
-                                                       BSEC_DBGSWGEN);
-
-               if (result != BSEC_OK) {
-                       ERROR("Error enabling DBGSWGEN\n");
-                       return -1;
-               }
+       if ((bsec_read_debug_conf() & BSEC_DBGSWGEN) == 0U) {
+               INFO("Software access to all debug components is disabled\n");
+               return -1;
        }
 
        mmio_setbits_32(RCC_BASE + RCC_DBGCFGR, RCC_DBGCFGR_DBGCKEN);
@@ -84,25 +72,3 @@ int stm32mp1_dbgmcu_get_chip_dev_id(uint32_t *chip_dev_id)
 
        return 0;
 }
-
-/*
- * @brief  Freeze IWDG2 in debug mode.
- * @retval None.
- */
-int stm32mp1_dbgmcu_freeze_iwdg2(void)
-{
-       uint32_t dbg_conf;
-
-       if (stm32mp1_dbgmcu_init() != 0) {
-               return -EPERM;
-       }
-
-       dbg_conf = bsec_read_debug_conf();
-
-       if ((dbg_conf & (BSEC_SPIDEN | BSEC_SPINDEN)) != 0U) {
-               mmio_setbits_32(DBGMCU_BASE + DBGMCU_APB4FZ1,
-                               DBGMCU_APB4FZ1_IWDG2);
-       }
-
-       return 0;
-}