Hello,
I have a similar issue as described here. I am able to connect with the JLink GDB server to KM0. However, connection to KM4 can’t be established. The output log shows:
SEGGER J-Link GDB Server V7.98d GUI Version
JLinkARM.dll V7.98d (DLL compiled Aug 14 2024 15:00:38)
-----GDB Server start settings-----
GDBInit file: none
GDB Server Listening port: 2335
SWO raw output listening port: 2332
Terminal I/O port: 2333
Accept remote connection: localhost only
Generate logfile: off
Verify download: off
Init regs on start: off
Silent mode: off
Single run mode: off
Target connection timeout: 5000 ms
------J-Link related settings------
J-Link Host interface: USB
J-Link script: AP2_KM4.JLinkScript
J-Link settings file: none
------Target related settings------
Target device: Cortex-M33
Target device parameters: none
Target interface: SWD
Target interface speed: 4000kHz
Target endian: little
Connecting to J-Link...
J-Link is connected.
Firmware: J-Link V11 compiled May 28 2024 15:36:02
Hardware: V11.00
S/N: 821006138
Feature(s): GDB
Checking target voltage...
Target voltage: 3.36 V
Listening on TCP/IP port 2335
Connecting to target...
ERROR: Could not connect to target.
Target connection failed. GDBServer will be closed...
As mentioned in the linked thread, I tried to flash the firmware again to the board, both project_lp and project_hp. The flashing process is succesfull for both. However, I am still not able to connect to KM4 with JLink.
I found out that AN0400 mentiones in section 1.9.3 this:
For KM4, you need to use the “monitor reset” instruction in corresponding rtl_gdb_debug.txt first (this process is similar to the process
of KM0). Then, set the bit[25] of memory address 0x4800_03f8 to 1 because the boot process of KM4 is controlled by the KM0. Without
this operation, the KM4 can't jump out of the boot function. Details of this operation are as follows: After executing “make debug”
instruction, a debug window pops up. In this window. Set bit[25] to 1, then type “c”, the KM4 is reset. refer to Fig 1-32 for more
information.
Only resetting KM0 may cause KM4 to work in an abnormal way because KM0 reboot will change some settings of KM4. If you find KM4
doesn’t work after KM0 reboot, you should reset KM4.
I connected to KM0 and manually set the bit[25] to 1 using
(gdb) x 0x480003f8
0x480003f8: 0x00000201
(gdb) set {uint32_t}0x480003f8 = 0x2000201
(gdb) x 0x480003f8
0x480003f8: 0x02000201
But KM4 didn’t recover even after a reset. Is there another procedure how to allow KM4 to jump out of the boot function? Are there another peculiarities which are not mentioned in this post? Is there another option which could enable KM4 to run properly?
Thank you in advance.