ref: a30b9999606a95dfdc73c4ae0264c2fecdb992c0
dir: /libc/src/sys/amd64-sysv-linux/syscall.awk/
# This job is very easy because app and kernel ABI are identical
# until the 4th parameter, so we only have to set the syscall
# number in rax
/^#/ {next}
{name=$2 ".s"
printf ".global %s\n" \
"%s:\n" \
"\tmovq\t$%d,%%rax\n" \
"\tsyscall\n" \
"\tret\n", $2, $2, $1 > name
close(name)}