Want to know how to replace string literal in compiled hex file

RE: Want to know how to replace string literal in compiled hex file

hmolesworth — Mon, 21 Nov 2022 16:56:22 GMT

The Device Name is not in the SoftDevice but typically in the Application, although if only a single hex file is available that will include the SoftDevice. The Device Name usage can be explained by looking here, for example:

ble-advertising-a-beginners-tutorial

If lucky the device name is held in user data in UICR and not in the hex file, similar to (say) a MAC address:

// Some manufacturers define a MAC address within NRF_UICR
// The 6-byte BLE Radio MAC address is stored in the nRF52832 UICR at NRF_UICR_BASE+0x80 LSB first.
// address during programming. Important: if full memory protection is enabled, not allowing the UICR to be read via the SWD interface.
// UICR Register:
// NRF_UICR + 0x80 (0x10001080): MAC_Addr [0] (0xZZ)
// NRF_UICR + 0x81 (0x10001081): MAC_Addr [1] (0xYY)
// NRF_UICR + 0x82 (0x10001082): MAC_Addr [2] (0xXX)
// NRF_UICR + 0x83 (0x10001083): MAC_Addr [3] (0x93)
// NRF_UICR + 0x84 (0x10001084): MAC_Addr [4] (0x54)
// NRF_UICR + 0x85 (0x10001085): MAC_Addr [5] (0x94)

Searching the UICR region might locate the Device Name .. unlikely though.

RE: Want to know how to replace string literal in compiled hex file

Sigurd — Mon, 21 Nov 2022 12:04:30 GMT

[quote user="robogo"]"What the method of string encoding by the compiler?"[/quote]

I would guess that depends on the compiler. SES supports AFAIK, both GCC and SEGGER Compiler. I think it's better to spend the time to get the source code and compile it.

RE: Want to know how to replace string literal in compiled hex file

robogo — Fri, 18 Nov 2022 17:11:43 GMT

we are. since tjhe bluetooth module is nordic's code, I told the student teams to contact both Qorvo and Segger to get the compiler going.

Can you just answer the question, "What the method of string encoding by the compiler?"
I thought Nordic would be best placed to ask.

RE: Want to know how to replace string literal in compiled hex file

Sigurd — Fri, 18 Nov 2022 16:23:01 GMT

Hi,

We can not help reverse engineer a hex file. Maybe you can ask for help on how to compile the source code at the same place you found the hex file.