You are at the office, at a client’s site, at a school, or visiting your mom. Suddenly, for some strange reason, you need to edit a hex file. We don’t know why, but if you are reading Hackaday, it isn’t that big of a stretch to imagine it.
Object files can be linked with one another, but addresses are lost. Relocatable files contain the address in the sh_addr field of a section. Executable files maintain address bindings and can be directly loaded. (The object file must have a memory width of 8 bits.) See TI-TXT Hex Format (–ti_txt Option). (The object file must have a memory width of 16 bits.) See Texas Instruments SDSMAC (TI-Tagged) Object Format (–ti_tagged Option). The structure in this sense is defined by the linker script or configuration used to build the code. The file containing this code/data may be raw binary, or an encoded binary format such as Intel Hex or Motorola S-Record for example.
After the device is opened, turn it on and look for a blinking led on the circuit board inside of the device. If you see a blinking led, the device should be good and the firmware is running fine, you may close the device and double check the troubleshooting instructions. We only want to open the device if it’s absolutely necessary, so to make sure, please reset ping-viewer settings, and connect the device to the computer again. If ping-viewer detects the device automatically, there is no problem!
When we branch to our cave, those stolen instructions will be run in the epilogue of our evil function before returning to the scene of the crime. Patching with Ghidra
IN our experiment, we now had the max temperature variable, so we figured we’d patch that and be done. This turned out to not be the case, but let’s see how to go about it now. The reverse engineer only needs to right click the assembly line they wish to change and click Patch Instruction.