| #include <stdio.h> |
| |
| char buffer[] ="0123456789abcdef"; |
| char target[] ="XXXXXXXXXXXXXXXX"; |
| |
| int main(void) |
| { |
| setbuf(stdout, NULL); |
| |
| printf("------- Copy 10+1 bytes from buffer to target\n"); |
| printf("------- EX to OR in the length\n"); |
| printf("before: buffer = |%s|\n", buffer); |
| printf("before: target = |%s|\n", target); |
| asm volatile( "larl 1, 1f\n\t" |
| "lghi 2, 10\n\t" |
| "ex 2, 0(1)\n\t" |
| "j 2f\n\t" |
| "1:\n\t" |
| "mvc 0(1,%0),0(%1)\n\t" |
| "2:\n\t" |
| : : "a" (target), "a" (buffer): "1", "2", "memory"); |
| printf("after: buffer = |%s|\n", buffer); |
| printf("after: target = |%s|\n", target); |
| printf("\n"); |
| |
| printf("------- EX 0,... has no effect (writes out target)\n"); |
| printf(" target = |"); |
| asm volatile( "lghi 0, 0xff\n\t" // fill nonsense in r0 |
| "larl 1, 1f\n\t" |
| "lghi 2, 1\n\t" // stdout |
| "lgr 3, %0\n\t" // target |
| "lghi 4, %1\n\t" // len |
| "ex 0, 0(1)\n\t" |
| "j 2f\n\t" |
| "1:\n\t" |
| "svc 4\n\t" |
| "2:\n\t" |
| : : "a" (target), "i" (sizeof target - 1) |
| : "0", "1", "2", "3", "4"); |
| printf("|\n"); |
| printf("\n"); |
| |
| printf("------- EX to OR in the syscall number (writes out target)\n"); |
| printf(" target = |"); |
| asm volatile( "lghi 5, 4\n\t" // NR_write |
| "larl 1, 1f\n\t" |
| "lghi 2, 1\n\t" // stdout |
| "lgr 3, %0\n\t" // target |
| "lghi 4, %1\n\t" // len |
| "ex 5, 0(1)\n\t" |
| "j 2f\n\t" |
| "1:\n\t" |
| "svc 0\n\t" // changed to NR_write |
| "2:\n\t" |
| : : "a" (target), "i" (sizeof target - 1) |
| : "1", "2", "3", "4", "5"); |
| printf("|\n"); |
| printf("\n"); |
| |
| return 0; |
| } |
| |