compilations

[kp7796]

Hello,
I have some confusion about compilations process in embedded system. Can please explain compilations process up to loader

[JosAH]

@kp7796
Normally you don't compile anything on the embedded system itself. You 'cross compile' on a host (e.g. a PC) and transfer the compiled files to your embedded system.

The embedded system has a loader; some of them can link your compiled files and some don't, if not you have to link your compiled files on your host system after compilation.

The loader loads the image (and possibly relocates symbolic addresses) and starts the process.

kind regards,

Jos

[donbock]

@JosAH
In the old days you might download the program image from the host computer to a COTS "prom burner" over a serial line, use that device to copy the program image into a memory device (PROM or EPROM), and then manually install the memory device in the target system with a "screw driver".

This procedure is still done today; but you're more likely to use a loader program that is always resident in the target system to download the program image from the host computer directly into flash memory in the target system.

In the much older days you might use punch cards or paper tape as the transfer medium, but that bit of nostalgia only has relevance to my misspent youth ...

[JosAH]

@donbock
Note how I left out the means of the transfer in my previous paragraph: "transfer the compiled files to your embedded system." ;-) I know these PROM programmers: it took several minutes to program 4KB in total and sometimes it even failed ...

@donbock
I dropped 4000 puch cards (unmarked) when I ran down the stairs carrying them on my arm. It took me hours to sort them again ;-) btw, have you ever used those old PLAs (Programmable Logic Arrays)? They were amazingly fast but you could throw them away if your program contained a bug. Those were the days ;-)

kind regards,

Jos