flash/stm32l4x: STM32L5 support programming when TZEN=1 and RDP=0x55

when RDP level is 0.5 the provided work-area should reside in non-secure RAM
to ensure that:
 - add a hint in the driver level
 - reduce the usage of secure RAM only when TZEN=1 and RDP is not 0.5
   (check the target configuration file)

Change-Id: Idbf2325e609b84ef8480eefdb49a176fdf7e07c7
Signed-off-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6035
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Tested-by: jenkins

diff --git a/src/flash/nor/stm32l4x.c b/src/flash/nor/stm32l4x.c
index db8d5e78d3175d5ecf010b5e06ce7acf37c594c0..de36d56c71796af5130835af7010190577e7dd17 100644 (file)
--- a/src/flash/nor/stm32l4x.c
+++ b/src/flash/nor/stm32l4x.c
@@ -1434,6 +1434,13 @@ static int stm32l4_write(struct flash_bank *bank, const uint8_t *buffer,
        if (retval != ERROR_OK)
                goto err_lock;
 
+       /* For TrustZone enabled devices, when TZEN is set and RDP level is 0.5,
+        * the debug is possible only in non-secure state.
+        * Thus means the flashloader will run in non-secure mode,
+        * and the workarea need to be in non-secure RAM */
+       if (stm32l4_info->tzen && (stm32l4_info->rdp == RDP_LEVEL_0_5))
+               LOG_INFO("RDP level is 0.5, the work-area should reside in non-secure RAM");
+
        retval = stm32l4_write_block(bank, buffer, offset, count / 8);
 
 err_lock:

diff --git a/tcl/target/stm32l5x.cfg b/tcl/target/stm32l5x.cfg
index 02297e36996fed5d0f7dd262874ff5b871d87886..0616df1cbabe7808f11483a4867be28f18ea1a8d 100644 (file)
--- a/tcl/target/stm32l5x.cfg
+++ b/tcl/target/stm32l5x.cfg
@@ -173,7 +173,11 @@ $_TARGETNAME configure -event gdb-flash-erase-start {
        } {
                ahb_ap_secure_access
                echo "TZEN option bit enabled"
-               set use_secure_workarea 1
+
+               # check if FLASH_OPTR.RDP is not Level 0.5
+               if {[expr {$FLASH_OPTR & 0xFF}] != 0x55} {
+                       set use_secure_workarea 1
+               }
        }
 
        set workarea_addr [$_TARGETNAME cget -work-area-phys]