Enabling JTAG Support on Secure Targets
On secure targets, where the ODM production fuse has been blown, MB1 locks the JTAG connection interface. To enable the JTAG interface on such a target, a special BCT is required where certain parameters are set.
To enable the JTAG interface on a secure target
- Set the desired debugging features through the BCT section of the flashing configuration file.
- Generate a new BCT image.
To enable debugging features through the BCT configuration file
- In the BCT partition of the flashing configuration file, set the uid attribute to the UID of the target device if needing to update the debug features in u32_secure_debug_control_ecid_checked.
- Set either u32_secure_debug_control_not_ecid_checked or u32_secure_debug_control_ecid_checkedfields to specify the debugging features desired.
The u32_secure_debug_control_not_ecid_checked
attribute collection of bit
fields are as follows.
Bits | Feature enabled by a ‘1’ bit |
---|---|
31:18 | Reserved |
17 | FSI non-secure NIDEN |
16 | Reserved |
15 | APE secure debug |
14 | DCE secure debug |
13 | Reserved |
12 | PVA0 secure debug |
11 | RCE secure debug |
10 | SCE secure debug |
9 | SPE secure debug |
8:5 | Reserved |
4 | NIDEN (disabled when DEBUG_AUTHENTICATION[1] fuse set) |
3:0 | Reserved |
The u32_secure_debug_control_ecid_checked
attribute collection of bit
fields are as follows.
Bits | Feature enabled by a ‘1’ bit |
---|---|
31 | Ramdump |
30:26 | Reserved |
25 | FSI secure NIDEN |
24 | FSI secure DBGEN |
23:20 | FSI Cluster core debug [3:0] |
19 | FSI non-secure HNIDEN |
18 | FSI non-secure HIDEN |
17 | FSI non-secure NIDEN |
16 | FSI non-secure DBGEN |
5 | DBGEN |
4 | NIDEN |
3 | SPIDEN |
2 | SPNIDEN |
1 | DEVICEEN |
0 | JTAG_ENABLE |
On secure targets MB1 compares the UID of the chip to the UID in the BCT and enables debug
features for u32_secure_debug_control_ecid_checked
if the UIDs match. The
MB1 enables debug features for u32_secure_debug_control_non_ecid_checked
without verifying the UID.
An example of a flashing configuration file, that specifies the UID value for a specific
target device, to enable the JTAG interface with all features in
u32_secure_debug_control_ecid_checked
except Ramdump
, is
as follows:
[partition]
name=bct
allocation_policy=sequential
filesystem_type=basic
uid=0xa18010016419f105000000000a010380
u32_secure_debug_control_ecid_checked=0x03FF003F
size=0x80000
partition_attribute=0