I feel like this should be really simple, but something is tripping me up.
This code sets up my GP register. It's used for relative addressing elsewhere in the code.
movhi 0xFFFF, r0, gp
movea 0, gp, gp
R0 is a 'zero register'. IE, the contents are always zero.
Here's the descriptions for the two instructions.
MOVHI : Adds a word data, whose higher 16 bits are specified by the 16-bit immediate data and lower
16 bits are 0, to the word data of general register reg1 and stores the result in general register
reg2.
MOVEA: Adds the 16-bit immediate data, sign-extended to word length, to the word data of general
register reg1, and stores the result to general register reg2.
Based on the reference manual, I think GP should be 0xFFFF0000 when this is all done. Based on what little I've found on the web, this is just some compiler weirdness used to generate a 32 bit address.
Problem being, using this as a base for relative addressing later in the code generates invalid addresses.
So either there's some nuance of these opcodes that I'm missing, or my code dump is damaged in some way. 95% of my code seems to have disassembled correctly, but there's still some other quirks I can't quite account for.
If anyone has any insight, I'd appreciate it. This seems like it should be really simple, which is making me even more frustrated.
