What directives should I use in GAS? I’ve found the ‘.org’ directive but GAS doesn’t seem to have a ‘.bits’ directive. The assembler defaults to 64–bit for me, you can use –32 or –64 to chose on the command line. Have a look at the manual for as to see how you can change the … Read more
It appears you found your example for creating a bootable ISO image from this StackOverflow Answer. Unfortunately you picked an accepted answer that is incorrect in many ways. Pretend you never saw that answer. On most Linux distros either a program called genisoimage or mkisofs exists. These days they are actually the same program. Whichever … Read more
Looking at the nasm source, it looks like: ‘oword”https://stackoverflow.com/”DO’ is 8 times as big as “word” (O for “octoword”), synonymous with dqword (“double-quad”); that would be 128 bits, corresponding to the size of an SSE vector register. ‘tword”https://stackoverflow.com/”DT’ is 80 bits (T for “ten bytes”), the full size of an Intel x87 floating point register. … Read more
If you’re using nasm 2.11.08, there is a issue documented here to do with relative addressing combined with multiple entries in the data section. You can do one (or both) of two things to be certain. First, you can have a look at the generated assembler code to investigate what it’s actually churning out. That’s … Read more