ARM 设置SVC 0x123456出错

Question

    AREA    BL_instruction, CODE, READWRITE
    ENTRY

    ADR     r4,P
    ADR     r5,Q

    LDR     r0,[r4]
    BL      Func1
    STR     r0,[r4,#8]
    ;
    ;
    ;
    LDR     r0,[r5]
    BL      Func1
    STR     r0,[r0,#8]

    MOV     r0,#0x18
    LDR     r1,=0x20026
    SWI     #0x123456

    END


Func1   CMP     r0,#0
        MOVGT   r0,r0,  LSL #4
        ADDGT   r0,r0,#1
        MOVLT   r0,r0,  LSL #5
        MOV     pc,r14

    AREA    BL_instruction, DATA, READWRITE
P   DCD     0x00000003      ;P=3
Q   DCD     0xFFFFFFFF      ;Q=-1
    SPACE   8

Answer 1

https://blog.csdn.net/pan0755/article/details/77051093