Eclipse, GDB, MacOS...So Close...

[Jim]

I am seeing signs of the chip wanting to be debugged by Eclipse on my Mac. It really does. I can feel it.

Two things seem to be plaguing me:

1. 90% of the time it fails to download the code from gdb, citing a "block verification error". Would like to get to the bottom of this.

2. Once in a while it successfully downloads, then it breaks at the reset handler. I don't know why (I haven't set any breakpoints), but it shows me where it is and is looking like it might be starting to work.

Then I hit "resume", and I get this:

Read 2 bytes @ address 0x000003D4 (Data = 0x50D0)
Read 2 bytes @ address 0x000003D6 (Data = 0xDCFB)
Read 2 bytes @ address 0x000003D8 (Data = 0x4805)
Read 2 bytes @ address 0x000003DA (Data = 0x4780)
Starting target CPU...
ERROR: Programming failed @ address 0x00000000 (block verification error)
...Target halted (PC = 0xFFFFFFFE)
Reading all registers
Read 4 bytes @ address 0xFFFFFFFE (Data = 0x00007FFF)
Read 4 bytes @ address 0x1FFFFFFC (Data = 0x00000000)
Reading 64 bytes @ address 0x1FFFFFC0
Read 4 bytes @ address 0x00000000 (Data = 0x20004000)
Read 2 bytes @ address 0xFFFFFFFE (Data = 0x0000)
Read 2 bytes @ address 0x00000000 (Data = 0x4000)
Read 2 bytes @ address 0x00000002 (Data = 0x2000)
Read 2 bytes @ address 0x00000004 (Data = 0x03BD)

It starts the target CPU again, and I get another block verification error. What is it trying to download to address 0?

My gdb startup script looks like this:

mon speed 30 mon endian little mon flash download = 1 mon flash device = NRF51822 mon sleep 1000 mon reset 0 mon sleep 1000

The sleeps seem to help, but this is starting to feel like a bad game of whack-a-mole.

Any ideas?

[Jim]

Update: running gdb locally, connecting to the JLink GDB server, seems to work quite robustly. An ugly way to debug, but maybe better than nothing.

I'm running the same gdb from the command line that I am telling eclipse to use, with the same commands in the startup script. Suspicious. Timing maybe?

[Jim]

I love answering my own questions.

I took a chance at trying the "Standard GDB Hardware Debugging Launcher" instead of the "GDB (DSF) Hardware Debugging Launcher" that NAN-29 suggests. This is a little bit of fine print at the bottom of the "Main" tab in the debug configuration editor. You have to override the default.

And voila, it works within eclipse, and seemingly quite well. I'm only debugging blinky right now; I'll take on a real BLE sample next, but I am no longer slowly going insane trying random settings.

I hope this helps any of you out there trying to use your mac for development.

-Jim

[Ole Morten]

Thanks for updating with this! Feel free to also accept your own answer, if it is useful!

[Carles]

Jim, that was a great couple of posts :)

[jdavid75]

I have the same problem but in Windows 7. My Segger output looks like this:

SEGGER J-Link GDB Server V5.02d Command Line Version

JLinkARM.dll V5.02d (DLL compiled Sep 18 2015 20:21:49)

-----GDB Server start settings----- GDBInit file: none GDB Server Listening port: 2331 SWO raw output listening port: 2332 Terminal I/O port: 2333 Accept remote connection: localhost only Generate logfile: off Verify download: on Init regs on start: on Silent mode: off Single run mode: on Target connection timeout: 0 ms ------J-Link related settings------ J-Link Host interface: USB J-Link script: none J-Link settings file: none ------Target related settings------ Target device: Cortex-M4 Target interface: SWD Target interface speed: 1000kHz Target endian: little

Connecting to J-Link... J-Link is connected. Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Aug 28 2015 19:26:24 Hardware: V1.00 S/N: 682869800 Checking target voltage... Target voltage: 3.30 V Listening on TCP/IP port 2331 Connecting to target...Connected to target Waiting for GDB connection...Connected to 127.0.0.1 Reading all registers Read 4 bytes @ address 0x00000000 (Data = 0xFFFFFFFF) Target interface speed set to 1000 kHz Resetting target Halting target CPU... ...Target halted (PC = 0xFFFFFFFE) R0 = 00000000, R1 = 00000000, R2 = 00000000, R3 = 00000000 R4 = 00000000, R5 = 00000000, R6 = 00000000, R7 = 00000000 R8 = 00000000, R9 = 00000000, R10= 00000000, R11= 00000000 R12= 00000000, R13= FFFFFFFC, MSP= FFFFFFFC, PSP= 00000000 R14(LR) = FFFFFFFF, R15(PC) = FFFFFFFE XPSR 01000000, APSR 00000000, EPSR 01000000, IPSR 00000000 CFBP 00000000, CONTROL 00, FAULTMASK 00, BASEPRI 00, PRIMASK 00 Reading all registers Read 4 bytes @ address 0xFFFFFFFE (Data = 0xFFFF0000) Select auto target interface speed (1000 kHz) Flash breakpoints enabled Semi-hosting enabled (Handle on BKPT) Semihosting I/O set to TELNET Client Read 4 bytes @ address 0xFFFFFFFE (Data = 0xFFFF0000) Downloading 3244 bytes @ address 0x00000000 - Verify failed Downloading 8 bytes @ address 0x00000CAC - Verify failed Downloading 1344 bytes @ address 0x00000CB4 - Verify failed Writing register (PC = 0x00000a18) Read 4 bytes @ address 0x00000A18 (Data = 0xFFFFFFFF) Read 2 bytes @ address 0x000008E6 (Data = 0xFFFF) Read 2 bytes @ address 0x000008E6 (Data = 0xFFFF) Resetting target Halting target CPU... ...Target halted (PC = 0xFFFFFFFE) Read 2 bytes @ address 0x000008E6 (Data = 0xFFFF) Read 2 bytes @ address 0x000008E6 (Data = 0xFFFF) Read 2 bytes @ address 0x000008E6 (Data = 0xFFFF) R0 = 00000000, R1 = 00000000, R2 = 00000000, R3 = 00000000 R4 = 00000000, R5 = 00000000, R6 = 00000000, R7 = 00000000 R8 = 00000000, R9 = 00000000, R10= 00000000, R11= 00000000 R12= 00000000, R13= FFFFFFFC, MSP= FFFFFFFC, PSP= 00000000 R14(LR) = FFFFFFFF, R15(PC) = FFFFFFFE XPSR 01000000, APSR 00000000, EPSR 01000000, IPSR 00000000 CFBP 00000000, CONTROL 00, FAULTMASK 00, BASEPRI 00, PRIMASK 00 Reading all registers Read 4 bytes @ address 0xFFFFFFFE (Data = 0xFFFF0000) Setting breakpoint @ address 0x000008E6, Size = 2, BPHandle = 0x0001 Starting target CPU... ...Target halted (PC = 0xFFFFFFFE) Reading all registers Read 4 bytes @ address 0xFFFFFFFE (Data = 0xFFFFFFFF) Removing breakpoint @ address 0x000008E6, Size = 2 Read 4 bytes @ address 0xFFFFFFF4 (Data = 0x00000000) Read 4 bytes @ address 0xFFFFFFF0 (Data = 0x00000000) Read 4 bytes @ address 0x00000000 (Data = 0xFFFFFFFF) Reading 64 bytes @ address 0x00000000 Reading 64 bytes @ address 0x00000040 Read 4 bytes @ address 0xFFFFFFEC (Data = 0x00000000) Read 4 bytes @ address 0xFFFFFFEC (Data = 0x00000000) Read 4 bytes @ address 0x00000000 (Data = 0xFFFFFFFF) Read 4 bytes @ address 0xFFFFFFF4 (Data = 0x00000000) Read 4 bytes @ address 0xFFFFFFEC (Data = 0x00000000) Read 4 bytes @ address 0x00000000 (Data = 0xFFFFFFFF) Reading 64 bytes @ address 0xFFFFFF80 Reading 64 bytes @ address 0xFFFFFFC0