sysstub.ph

来自「klibc精简化的c程序库」· PH 代码 · 共 38 行

# -*- perl -*-
#
# arch/alpha/sysstub.ph
#
# Script to generate system call stubs
#

# On Alpha, most system calls follow the standard convention, with the
# system call number in r0 (v0), return an error value in r19 (a3) as
# well as the return value in r0 (v0).
#
# A few system calls are dual-return with the second return value in
# r20 (a4).

sub make_sysstub($$$$$@) {
    my($outputdir, $fname, $type, $sname, $stype, @args) = @_;

    $stype = $stype || 'common';
    $stype = 'common' if ( $stype eq 'dual0' );

    open(OUT, '>', "${outputdir}/${fname}.S");
    print OUT "#include <asm/unistd.h>\n";
    print OUT "#include <machine/asm.h>\n";
    print OUT "\n";
    print OUT "\t.text\n";
    print OUT "\t.type ${fname},\@function\n";
    print OUT "\t.ent\t${fname}, 0\n"; # What is this?
    print OUT "\t.globl ${fname}\n";
    print OUT "${fname}:\n";
    print OUT "\tlda\tv0, __NR_${sname}(zero)\n";
    print OUT "\tbr __syscall_${stype}\n";
    print OUT "\t.size\t${fname},.-${fname}\n";
    print OUT "\t.end\t${fname}\n";
    close(OUT);
}

1;