Add build system scaffolding and libc headers

1 files changed, 59 insertions, 0 deletions

diff --git a/lib/libc/include/syscall.h b/lib/libc/include/syscall.h
new file mode 100644
index 00000000..645c4bcd
--- /dev/null
+++ b/lib/libc/include/syscall.h
@@ -0,0 +1,59 @@
+#ifndef __LIBC_SYSCALL_H
+#define __LIBC_SYSCALL_H
+
+#include <asm/syscall.h>
+#include <asm/unistd_64.h>
+#include <errno.h>
+
+typedef long syscall_arg_t;
+
+#define __SYSCALL_NARGS_(a, b, c, d, e, f, g, h, n, ...) n
+#define __SYSCALL_NARGS(...) \
+	__SYSCALL_NARGS_(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0, )
+
+#define __SYSCALL_CONCAT_(a, b) a##b
+#define __SYSCALL_CONCAT(a, b)	__SYSCALL_CONCAT_(a, b)
+
+#define __SYSCALL_(b, ...) \
+	__SYSCALL_CONCAT(b, __SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
+
+#define __syscall(...) __SYSCALL_(__syscall_, __VA_ARGS__)
+#define syscall(...)   __syscall_ret(__syscall(__VA_ARGS__))
+
+#define __sa(x) ((syscall_arg_t)(x))
+
+#define __syscall_0(n)		__syscall0(__NR_##n)
+#define __syscall_1(n, a)	__syscall1(__NR_##n, __sa(a))
+#define __syscall_2(n, a, b)	__syscall2(__NR_##n, __sa(a), __sa(b))
+#define __syscall_3(n, a, b, c) __syscall3(__NR_##n, __sa(a), __sa(b), __sa(c))
+#define __syscall_4(n, a, b, c, d) \
+	__syscall4(__NR_##n, __sa(a), __sa(b), __sa(c), __sa(d))
+#define __syscall_5(n, a, b, c, d, e) \
+	__syscall5(__NR_##n, __sa(a), __sa(b), __sa(c), __sa(d), __sa(e))
+#define __syscall_6(n, a, b, c, d, e, f)                                  \
+	__syscall6(__NR_##n, __sa(a), __sa(b), __sa(c), __sa(d), __sa(e), \
+		   __sa(f))
+#define __syscall_7(n, a, b, c, d, e, f, g)                               \
+	__syscall7(__NR_##n, __sa(a), __sa(b), __sa(c), __sa(d), __sa(e), \
+		   __sa(f), __sa(g))
+
+static __inline long __syscall_ret(long ret)
+{
+	if (ret > -4096 && ret < 0) {
+		errno = -ret;
+		ret = -1;
+	}
+	return ret;
+}
+
+#ifdef __NR_pread64
+#undef __NR_pread
+#define __NR_pread __NR_pread64
+#endif
+
+#ifdef __NR_pwrite64
+#undef __NR_pwrite
+#define __NR_pwrite __NR_pwrite64
+#endif
+
+#endif