hamdim wrote: ↑
Tue Jun 18, 2019 2:16 pm
I am trying to adapt a C project about Elliptic Curve Diffie-Helmen key exchange,
which uses registers, and when I tried to compile it, it says "there's no such registers name"
My Q is what are the registers I can use in Raspberry Pi 3 B (BCM2835) to temporarily store processed data instead of variables stored in RAM,
! not the register used to configure the GPIO
Thank you in advance !
Do you mean CPU registers?
These are R0 ... R15, of which R0 to R12 are useful (32 bits wide).
There are also 16 SIMD (NEON) registers (128 bits wide)
In 64 bit mode you get twice the number of registers. 31 integer and 32 SIMD. Register 31 is the zero register.
X0 ... X30 (64 bits) and W0 ... W30 (32 bits), XZR and WZR .
If you are programming in a language like C or C++ then the compiler will allocate and use the CPU registers very efficiently.
You can use the "register" keyword to force it to use a particular register, but its usually a bad idea.
Can you post a bit of the code that's in error?