flash Kinetis: Detect RESET/WDOG loop, fix detection of secured MCU

Kinetis driver checks MDM STAT register to detect secured state of MCU.
Original version often reported a blank device as secured one.
Change #3010 has not fixed all false reports.
After changes in arm_adi_v5 infrastructure secured devices was not detected
at all.

New algorithm uses multiple MDM STAT reads and counts MDM_STAT_SYSSEC and
MDM_STAT_FREADY bits. Both secured MCU and MCU locked-up in RESET/WDOG loop
are detected reliably.

Detection is run in both kx.cfg and klx.cfg from examine-start event,
not examine-end as before. Event is configured only for non hla adapter.

Minor fix in klx.cfg: commented out adapter_khz 24000 in reset-init.
Such frequency is not supported in VLPR CPU mode and with JTAG.

Change-Id: I2ec2b68c45bde9898159cd15fbdcbcfa538c41d9
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/3547
Tested-by: jenkins
Reviewed-by: Steven Stallion <stallion@squareup.com>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
This commit is contained in:
Tomas Vanek 2016-07-17 16:22:47 +02:00 committed by Andreas Fritiofson
parent 8285ec4cb0
commit 6d5b4d709c
3 changed files with 60 additions and 59 deletions

View File

@ -227,6 +227,8 @@ struct kinetis_flash_bank {
} flash_support;
};
#define MDM_AP 1
#define MDM_REG_STAT 0x00
#define MDM_REG_CTRL 0x04
#define MDM_REG_ID 0xfc
@ -261,7 +263,7 @@ static int kinetis_mdm_write_register(struct adiv5_dap *dap, unsigned reg, uint3
int retval;
LOG_DEBUG("MDM_REG[0x%02x] <- %08" PRIX32, reg, value);
retval = dap_queue_ap_write(dap_ap(dap, 1), reg, value);
retval = dap_queue_ap_write(dap_ap(dap, MDM_AP), reg, value);
if (retval != ERROR_OK) {
LOG_DEBUG("MDM: failed to queue a write request");
return retval;
@ -281,7 +283,7 @@ static int kinetis_mdm_read_register(struct adiv5_dap *dap, unsigned reg, uint32
{
int retval;
retval = dap_queue_ap_read(dap_ap(dap, 1), reg, result);
retval = dap_queue_ap_read(dap_ap(dap, MDM_AP), reg, result);
if (retval != ERROR_OK) {
LOG_DEBUG("MDM: failed to queue a read request");
return retval;
@ -575,9 +577,12 @@ COMMAND_HANDLER(kinetis_check_flash_security_status)
retval = kinetis_mdm_read_register(dap, MDM_REG_ID, &val);
if (retval != ERROR_OK) {
LOG_ERROR("MDM: failed to read ID register");
goto fail;
return ERROR_OK;
}
if (val == 0)
return ERROR_OK;
bool found = false;
for (size_t i = 0; i < ARRAY_SIZE(kinetis_known_mdm_ids); i++) {
if (val == kinetis_known_mdm_ids[i]) {
@ -589,17 +594,6 @@ COMMAND_HANDLER(kinetis_check_flash_security_status)
if (!found)
LOG_WARNING("MDM: unknown ID %08" PRIX32, val);
/*
* ... Read the MDM-AP status register until the Flash Ready bit sets...
*/
retval = kinetis_mdm_poll_register(dap, MDM_REG_STAT,
MDM_STAT_FREADY,
MDM_STAT_FREADY);
if (retval != ERROR_OK) {
LOG_ERROR("MDM: flash ready timeout");
goto fail;
}
/*
* ... Read the System Security bit to determine if security is enabled.
* If System Security = 0, then proceed. If System Security = 1, then
@ -610,33 +604,40 @@ COMMAND_HANDLER(kinetis_check_flash_security_status)
retval = kinetis_mdm_read_register(dap, MDM_REG_STAT, &val);
if (retval != ERROR_OK) {
LOG_ERROR("MDM: failed to read MDM_REG_STAT");
goto fail;
return ERROR_OK;
}
if ((val & (MDM_STAT_SYSSEC | MDM_STAT_CORE_HALTED)) == MDM_STAT_SYSSEC) {
LOG_WARNING("MDM: Secured MCU state detected however it may be a false alarm");
LOG_WARNING("MDM: Halting target to detect secured state reliably");
/*
* System Security bit is also active for short time during reset.
* If a MCU has blank flash and runs in RESET/WDOG loop,
* System Security bit is active most of time!
* We should observe Flash Ready bit and read status several times
* to avoid false detection of secured MCU
*/
int secured_score = 0, flash_not_ready_score = 0;
retval = target_halt(target);
if (retval == ERROR_OK)
retval = target_wait_state(target, TARGET_HALTED, 100);
if ((val & (MDM_STAT_SYSSEC | MDM_STAT_FREADY)) != MDM_STAT_FREADY) {
uint32_t stats[32];
int i;
if (retval != ERROR_OK) {
LOG_WARNING("MDM: Target not halted, trying reset halt");
target->reset_halt = true;
target->type->assert_reset(target);
target->type->deassert_reset(target);
for (i = 0; i < 32; i++) {
stats[i] = MDM_STAT_FREADY;
dap_queue_ap_read(dap_ap(dap, MDM_AP), MDM_REG_STAT, &stats[i]);
}
/* re-read status */
retval = kinetis_mdm_read_register(dap, MDM_REG_STAT, &val);
retval = dap_run(dap);
if (retval != ERROR_OK) {
LOG_ERROR("MDM: failed to read MDM_REG_STAT");
goto fail;
LOG_DEBUG("MDM: dap_run failed when validating secured state");
return ERROR_OK;
}
for (i = 0; i < 32; i++) {
if (stats[i] & MDM_STAT_SYSSEC)
secured_score++;
if (!(stats[i] & MDM_STAT_FREADY))
flash_not_ready_score++;
}
}
if (val & MDM_STAT_SYSSEC) {
if (flash_not_ready_score <= 8 && secured_score > 24) {
jtag_poll_set_enabled(false);
LOG_WARNING("*********** ATTENTION! ATTENTION! ATTENTION! ATTENTION! **********");
@ -648,17 +649,22 @@ COMMAND_HANDLER(kinetis_check_flash_security_status)
LOG_WARNING("**** command, power cycle the MCU and restart OpenOCD. ****");
LOG_WARNING("**** ****");
LOG_WARNING("*********** ATTENTION! ATTENTION! ATTENTION! ATTENTION! **********");
} else if (flash_not_ready_score > 24) {
jtag_poll_set_enabled(false);
LOG_WARNING("**** Your Kinetis MCU is probably locked-up in RESET/WDOG loop. ****");
LOG_WARNING("**** Common reason is a blank flash (at least a reset vector). ****");
LOG_WARNING("**** Issue 'kinetis mdm halt' command or if SRST is connected ****");
LOG_WARNING("**** and configured, use 'reset halt' ****");
LOG_WARNING("**** If MCU cannot be halted, it is likely secured and running ****");
LOG_WARNING("**** in RESET/WDOG loop. Issue 'kinetis mdm mass_erase' ****");
} else {
LOG_INFO("MDM: Chip is unsecured. Continuing.");
jtag_poll_set_enabled(true);
}
return ERROR_OK;
fail:
LOG_ERROR("MDM: Failed to check security status of the MCU. Cannot proceed further");
jtag_poll_set_enabled(false);
return retval;
}
FLASH_BANK_COMMAND_HANDLER(kinetis_flash_bank_command)

View File

@ -29,14 +29,6 @@ swj_newdap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME cortex_m -chain-position $_CHIPNAME.cpu
# It is important that "kinetis mdm check_security" is called for
# 'examine-end' event and not 'eximine-start'. Calling it in 'examine-start'
# causes "kinetis mdm check_security" to fail the first time openocd
# calls it when it tries to connect after the CPU has been power-cycled.
$_CHIPNAME.cpu configure -event examine-end {
kinetis mdm check_security
}
$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
set _FLASHNAME $_CHIPNAME.flash
@ -49,14 +41,20 @@ adapter_khz 1000
reset_config srst_nogate
if {![using_hla]} {
# Detect secured MCU or boot lock-up in RESET/WDOG loop
$_CHIPNAME.cpu configure -event examine-start {
kinetis mdm check_security
}
# if srst is not fitted use SYSRESETREQ to
# perform a soft reset
cortex_m reset_config sysresetreq
}
$_TARGETNAME configure -event reset-init {
# Table 5-1. Clock Summary of KL25 Sub-Family Reference Manual
# specifies up to 24MHz for run mode; Table 17 of Sub-Family Data
# Sheet rev4 lists 25MHz as the maximum frequency.
adapter_khz 24000
}
# Table 5-1. Clock Summary of KL25 Sub-Family Reference Manual
# specifies up to 24MHz for run mode; Table 17 of Sub-Family Data
# Sheet rev4 lists 25MHz as the maximum frequency.
# Uncoment only if VLPR mode is not used
#$_TARGETNAME configure -event reset-init {
# adapter_khz 24000
#}

View File

@ -33,14 +33,6 @@ swj_newdap $_CHIPNAME cpu -irlen 4 -ircapture 0x1 -irmask 0xf -expected-id $_CPU
set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME cortex_m -chain-position $_CHIPNAME.cpu
# It is important that "kinetis mdm check_security" is called for
# 'examine-end' event and not 'eximine-start'. Calling it in 'examine-start'
# causes "kinetis mdm check_security" to fail the first time openocd
# calls it when it tries to connect after the CPU has been power-cycled.
$_CHIPNAME.cpu configure -event examine-end {
kinetis mdm check_security
}
$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
set _FLASHNAME $_CHIPNAME.flash
@ -51,6 +43,11 @@ adapter_khz 1000
reset_config srst_nogate
if {![using_hla]} {
# Detect secured MCU or boot lock-up in RESET/WDOG loop
$_CHIPNAME.cpu configure -event examine-start {
kinetis mdm check_security
}
# if srst is not fitted use SYSRESETREQ to
# perform a soft reset
cortex_m reset_config sysresetreq