1 #include <stdio.h>
2 
3 char buffer[] ="0123456789abcdef";
4 char target[] ="XXXXXXXXXXXXXXXX";
5 
main(void)6 int main(void)
7 {
8    setbuf(stdout, NULL);
9 
10    printf("------- Copy 10+1 bytes from buffer to target\n");
11    printf("------- EXRL to OR in the length\n");
12    printf("before: buffer = |%s|\n", buffer);
13    printf("before: target = |%s|\n", target);
14    asm volatile( "lghi 2, 10\n\t"
15                  ".insn ril,0xc60000000000,2,1f\n\t" // exrl 2, 1f
16                  "j    2f\n\t"
17                  "1:\n\t"
18                  "mvc  0(1,%0),0(%1)\n\t"
19                  "2:\n\t"
20                  : : "a" (target), "a" (buffer) : "1", "2", "memory");
21    printf("after:  buffer = |%s|\n", buffer);
22    printf("after:  target = |%s|\n", target);
23    printf("\n");
24 
25    printf("------- EXRL 0,... has no effect (writes out target)\n");
26    printf("        target = |");
27    asm volatile( "lghi 0, 0xff\n\t" // fill nonsense in r0
28                  "lghi 2, 1\n\t"    // stdout
29                  "lgr  3, %0\n\t"   // target
30                  "lghi 4, %1\n\t"   // len
31                  ".insn ril,0xc60000000000,0,1f\n\t" // exrl 0, 1f
32                  "j    2f\n\t"
33                  "1:\n\t"
34                  "svc  4\n\t"       // NR_write
35                  "2:\n\t"
36                  : : "a" (target), "i" (sizeof target - 1)
37                  : "0", "2", "3", "4");
38    printf("|\n");
39    printf("\n");
40 
41    printf("------- EXRL to OR in the syscall number (writes out target)\n");
42    printf("        target = |");
43    asm volatile( "lghi 1, 4\n\t"    // NR_write
44                  "lghi 2, 1\n\t"    // stdout
45                  "lgr  3, %0\n\t"   // target
46                  "lghi 4, %1\n\t"   // len
47                  ".insn ril,0xc60000000000,1,1f\n\t" // exrl 1, 1f
48                  "j    2f\n\t"
49                  "1:\n\t"
50                  "svc  0\n\t"       // changed to NR_write
51                  "2:\n\t"
52                  : : "a" (target), "i" (sizeof target - 1)
53                  : "1", "2", "3", "4");
54    printf("|\n");
55    printf("\n");
56 
57    return 0;
58 }
59 
60