汇编基本指令的学习

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1:ldr 伪指令
LDR{cond}{.W} Rt, =expr
Rt ： is the register to be loaded.
expr ：evaluates to a numeric value.

2：ldr指令装载load 内存--》寄存器
op{type}{cond} Rt, [Rn {, #offset}] ; immediate offset
Rt ：is the register to load or store.

Rn ：is the register on which the memory address is based
例子：
LDR r8,[r10] ; loads R8 from the address in R10：把r8的数值放入r10所表示的地址。
.
LDRNE r2,[r5,#960]! ; (conditionally) loads R2 from a word 960 bytes above the address in R5, and increments R5 by 960.

3：str指令存储 store 寄存器--》内存
STR r2,[r9,#consta-struc] ：把r2的值存储到r9的地址constr-struc以上的地址。
consta-struc is an expression evaluating to a constant in the range 0-4095.

4：stm指令 ldm
stmdb :相当于stmfd 先pc减rn再放入sp中
stmia : 先把rn放入sp中，pc然后再加
ldmdb :
ldmia :ldmfd
DB (Decrement Before) IA (Increment After)
op{addr_mode}{cond} Rn{!}, reglist{^}

If ! is present, the final address is written back into Rn.
如果you感叹号把最终地址传给rn。
For example:
STMFD sp!, {r0-r5} ; Push onto a Full Descending Stack
LDMFD sp!, {r0-r5} ; Pop from a Full Descending Stack
5:宏
MACRO 宏名字
{$label} macroname{$cond} {$parameter{,$parameter}...}
; code
MEND
6：

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