moldypizza

That is a good question. I didn't really understand why I had to do this either for this project either. According to a git hub tutorial, link, it has to do with allowing room for setting up the stack and some debugging stuff. I don't think it should matter for this project because it doesn't use the stack, however when I tried to compile it without it didn't work. I have another instructable where I make a row of leds blink. In that it is more clear what the purpose of the kernel.ld is. In that project, the source code I wrote does have a .text section in it because to use the stack you have manually set aside space for it. So all of you code is inserted after 0x8000 and then sp (stack pointer) is moved to 0x8000. You can see the effect of it on the kernel.elf in the attached image. ...

That is a good question. I didn't really understand why I had to do this either for this project either. According to a git hub tutorial, link, it has to do with allowing room for setting up the stack and some debugging stuff. I don't think it should matter for this project because it doesn't use the stack, however when I tried to compile it without it didn't work. I have another instructable where I make a row of leds blink. In that it is more clear what the purpose of the kernel.ld is. In that project, the source code I wrote does have a .text section in it because to use the stack you have manually set aside space for it. So all of you code is inserted after 0x8000 and then sp (stack pointer) is moved to 0x8000. You can see the effect of it on the kernel.elf in the attached image. Everything before the 0x8000 line is 0 or null, then you can see that after that line the code is inserted. The objcopy just translates the .elf into a binary format. This is done because the raspberry pi looks for a binary image file. So even though the .img does not have a 0x8000 address it is still telling the raspberry pi to partition the memory the way you told it to. So .text or code after 0x8000 and everything before 0x8000 is left empty. I hope that sort of answered your questions. Feel free to message me with any other questions or post them here and I will try my best to answer them. Unfortunately writing bare metal assembly for the raspberry pi 3 isn't very well documented.

Sorry about that. Instructables had a problem with the file not having an extension. I re-uploaded it as makefile.txt, just rename it "makefile" without the .txt and you should be good to go.

Thanks! I know it is sort of reinventing the wheel especially since this could be done with like 5 lines of python code but I enjoy learning about how things work on a low level.

What is that?