Intro to Assembly Language: Lecture Notes

Here are the General-Purpose CPU registers that we'll work with and their descriptions:

Register	Size	Typical Purpose (Convention)
`rax`	64-bit	Accumulator; return value; syscall number
`rbx`	64-bit	General-purpose
`rcx`	64-bit	Counter (loops, shifts)
`rdx`	64-bit	Data register; I/O length; syscall arguments
`rsi`	64-bit	Source index; pointer to input data
`rdi`	64-bit	Destination index; pointer to output data
`rbp`	64-bit	Base pointer (stack frame reference)
`rsp`	64-bit	Stack pointer (top of stack)
`r8`	64-bit	General-purpose; syscall arguments
`r9` to `r15`	64-bit	General-purpose