Also the part where you talk about “recovery mode” I think we referred to this as DFU mode back in the day. “Device firmware update” I’m not entirely sure it was called “recovery” at the time though I could be wrong as it’s been more than 15 years
DFU is implemented in the ROM; it is morally if not technically a subset of the open standard by the same name.
Recovery mode is implemented in iBoot; it provides mediated access to the command interpreter and some file-ish transfer capabilities.
Both are still in use; whilst the implementations have obviously evolved the fundamental interactions have not changed since the original Apple (not Samsung) ROMs.
I think DFU mode and recovery mode are different. In recovery mode the screen is initialized and displays the “connect to iTunes” image. In DFU mode the screen is blank; I think this is implemented by the bootrom and can be used to restore even iBoot.
ooo good point it’s been so long I might be misremembering. the reason I commented was because I thought you had to put the device in DFU to upload the image to the Media dir that was mounted rw. But again it’s been 15 years lol
