Registers¶
Following registers are supported by the ISA and assembler ABI.
| Register Name | ABI Name | Description |
|---|---|---|
x0 |
zero |
Hard-wired Zero |
x1 |
ra |
Return Address |
x2 |
sp |
Stack Pointer |
x3 |
gp |
Global Pointer |
x4 |
tp |
Thread Pointer |
x5–x7 |
t0–t2 |
Temporary Registers |
x8 |
s0/fp |
Saved Register/Frame Pointer |
x9 |
s1 |
Saved Register |
x10–x11 |
a0–a1 |
Function Arg/Return Val Registers |
x12–x17 |
a2–a7 |
Function Arg Registers |
x18–x27 |
s2–s11 |
Saved Registers |
x28–x31 |
t3–t6 |
Temporary Registers |
Table 2.1: Registers with ABI acronyms
Register names are case-insensitive, so x5, X5, t0, and T0 are all equivalent.