ref: 09a34baac6757c7a4c33e3e3c50054acbb1b70bb
dir: /lib/sys/syscall+freebsd-x64.s/
.globl sys$syscall
sys$syscall:
/*
hack: We load 6 args regardless of
how many we actually have. This may
load junk values, but if the syscall
doesn't use them, it's going to be
harmless.
*/
movq %rdi,%rax
/* 8(%rsp): hidden type arg */
movq 16(%rsp),%rdi
movq 24(%rsp),%rsi
movq 32(%rsp),%rdx
movq 40(%rsp),%r10
movq 48(%rsp),%r8
movq 56(%rsp),%r9
syscall
jae .success
negq %rax
.success:
ret
/*
* pipe() syscall returns the pipes created in eax:edx, and
* needs to copy them to the destination locations manually.
*/
.globl sys$__freebsd_pipe
sys$__freebsd_pipe:
movq $0x2a,%rax
syscall
jae .pipesuccess
negq %rax
.pipesuccess:
movl %eax,(%rdi)
movl %edx,4(%rdi)
xorq %rax,%rax
ret