Recover from BlackMagic probe does not work

[joric]

Module E73-2G4M04S1B

Black Magic Probe (Firmware v1.6.1-267-g302ff20) (Hardware Version 0).

arm-none-eabi-gdb 8-2018-q4-major) 8.2.50.20181213-git

nrfjprog --recover works, arm-none-eabi-gdb does not.

The probe works (attaches just fine after nrfjprog --recover from J-Link).

arm-none-eabi-gdb.exe --quiet --batch -ex "target extended-remote \\.\COM8" -ex "set non-stop on" -ex "mon swdp_scan" -ex "att 2" -ex "mon erase_mass"
Target voltage: unknown                    
Available Targets:                         
No. Att Driver                             
 1      Nordic nRF52                       
 2      Nordic nRF52 Access Port           
Attaching to Remote target failed with: T05

Also posted to blackmagic-debug/blackmagic#230

[UweBonnes]

Why do you use some script coming from nowhere without further investigation? Did you attach by hand to port 2 and query the available commands as I requested before? It seems, not! A look at the source will tell you that port 2 has only one command:
const struct command_s nrf51_mdm_cmd_list[] = {
{"erase_mass", (cmd_handler)nrf51_mdm_cmd_erase_mass, "Erase entire flash memory"},
{NULL, NULL, NULL}
};
And what should "ex "set non-stop on" do here?

[joric]

It worked. Weird. Thanks. What did I do:

arm-none-eabi-gdb.exe
For help, type "help".                                                                
Type "apropos word" to search for commands related to "word".                         
(gdb) target extended-remote \\.\COM8                                                 
Remote debugging using \\.\COM8                                                       
(gdb) mon swdp_scan                                                                   
Target voltage: unknown                                                               
Available Targets:                                                                    
No. Att Driver                                                                        
 1      ARM Cortex-M                                                                  
 2      Nordic nRF52 Access Port                                                      
(gdb) attach 2                                                                        
Attaching to Remote target                                                            
warning: while parsing target description: no element found                           
warning: Could not load XML target description; ignoring                              
PC register is not available                                                          
(gdb) mon help                                                                        
General commands:                                                                     
        version -- Display firmware version info                                      
        help -- Display help for monitor commands                                     
        jtag_scan -- Scan JTAG chain for devices                                      
        swdp_scan -- Scan SW-DP for devices                                           
        targets -- Display list of available targets                                  
        morse -- Display morse error message                                          
        halt_timeout -- Timeout (ms) to wait until Cortex-M is halted: (Default 2000) 
        connect_srst -- Configure connect under SRST: (enable|disable)                
        hard_srst -- Force a pulse on the hard SRST line - disconnects target         
        traceswo -- Start trace capture [(baudrate) for async swo]                    
Nordic nRF52 Access Port specific commands:                                           
        erase_mass -- Erase entire flash memory                                       
(gdb) mon erase_mass                                                                  
(gdb) quit                                              
A debugging session is active.                          
                                                        
        Inferior 1 [Remote target] will be detached.    
                                                        
Quit anyway? (y or n) y                                 
Detaching from program: , Remote target                 
[Inferior 1 (Remote target) detached]                   
                                                        
C:\SDK\gcc-arm-none-eabi-8-2018-q4-major-win32\bin>                        

Actual "erase_mass" took just a moment (I guess it just removed the protection bits). After that it became fully programmable and for al that I didn't need J-Link at all. Worked with E73-2G4M08S1C and E73-2G4M04S1B (both are new from the factory).

Thanks! I don't really know why batch didn't work, probably timings or something. Didn't need "set non-stop on" either.

[drelephant]

Probably OT a bit but what are the two boards in the bottom-right and bottom-left of that picture?

[joric]

Probably OT a bit but what are the two boards in the bottom-right and bottom-left of that picture?

• https://github.com/jpconstantineau/NRF52-Board/tree/master/EByte_E73_Batt_ErgoTravel
• https://github.com/joric/nrfmicro

The latter is mine, the former is nRF52832-based and does not have hardware USB, only charger.