| .text |
| .global __clone |
| .type __clone, %function |
| __clone: |
| # int clone(fn, stack, flags, arg, ptid, tls, ctid) |
| # a b c d e f g |
| # 3 4 5 6 7 8 9 |
| # pseudo C code: |
| # tid = syscall(SYS_clone,c,b,e,f,g); |
| # if (!tid) syscall(SYS_exit, a(d)); |
| # return tid; |
| |
| # create initial stack frame for new thread |
| clrrdi 4, 4, 4 |
| li 0, 0 |
| stdu 0,-32(4) |
| |
| # save fn and arg to child stack |
| std 3, 8(4) |
| std 6, 16(4) |
| |
| # shuffle args into correct registers and call SYS_clone |
| mr 3, 5 |
| #mr 4, 4 |
| mr 5, 7 |
| mr 6, 8 |
| mr 7, 9 |
| li 0, 120 # SYS_clone = 120 |
| sc |
| |
| # if error, negate return (errno) |
| bns+ 1f |
| neg 3, 3 |
| |
| 1: # if we're the parent, return |
| cmpwi cr7, 3, 0 |
| bnelr cr7 |
| |
| # we're the child. call fn(arg) |
| ld 3, 16(1) |
| ld 12, 8(1) |
| mtctr 12 |
| bctrl |
| |
| # call SYS_exit. exit code is already in r3 from fn return value |
| li 0, 1 # SYS_exit = 1 |
| sc |
