riscv指令

各个寄存器

寄存器	ABI名字	注释	Saver
x0	zero	Hard-wired zero，常数0
x1	ra	Return address	caller，调用函数的指令pc
x2	sp	Stack pointer	callee，被调用的函数指令pc
x3	gp	Global pointer
x4	tp	Thread pointer
x5	t0	Temporary/alternate link register	caller
x6	t1	Temporaries	caller
x7	t2	Temporaries	caller
x8	s0/fp	Saved register/frame pointer	caller
x9	s1	Saved register	caller
x10	a0	Function arguments/return values	caller
x11	a1	Function arguments/return values	caller
x12	a2	Function arguments	caller
x13	a3	Function arguments	caller
x14	a4	Function arguments	caller
x15	a5	Function arguments	caller
x16	a6	Function arguments	caller
x17	a7	Function arguments	caller
x18	s2	Saved registers	caller
x19	s3	Saved registers	caller
x20	s4	Saved registers	caller
x21	s5	Saved registers	caller
x22	s6	Saved registers	caller
x23	s7	Saved registers	caller
x24	s8	Saved registers	caller
x25	s9	Saved registers	caller
x26	s10	Saved registers	caller
x27	s11	Saved registers	caller
x28	t3	Temporaries	caller
x29	t4	Temporaries	caller
x30	t5	Temporaries	caller
x31	t6	Temporaries	caller

指令类型

常见指令

li

r[rd]=immediate，U型指令
例：00000413 解析为li s0,0，s0（r[8]）

auipc

r[rd]=immediate<<12+pc，U型指令
例：00009117 解析为auipc sp,0x9，sp（r[2]）

addi

r[rd]=immediate+r[rs1]，I型指令，immediate带符号位扩展
例：ffc10113 解析为addi sp,sp,-4 sp（r[2]）

jal

r[rd] = pc+4; pc += sext(offset)，J型指令，sext表符号位扩展
例：00c000ef 解析为jal ra,pc加完后的值
参考手册中英文