Hi -
for my application I need the ability to load code from a filesystem.
My problem is, that this works only with position independent code.
And as far as I know the nios2-gnutools don't support the generation of pic code.
To get around this, my approach so far is to 'patch' the elf-binary after linking.
I straightened out my issues with data access but I can't think of a way to get around the 'call' opcode for function calls.
In effect 'call' transfers execution to the constant address encoded in the opcode.
But for position independent code I need something of a pc-relative jump.
I know there is 'callr', but the compiler generated code doesn't provide the address in a register as needed by 'callr'.
And I can't modify the opcode, because I only have 1 instruction 'slot' available.
I can't insert new opcodes because this would break the (compiler calculated) intra-function branches.
My question is, has anybody previously tried to load code to an (at link time) unknown address, and what are your experiences?
Thanks,
Wolfgang
