tools/nolibc/arch: split arch-specific code into individual files

In order to ease maintenance, this splits the arch-specific code into
one file per architecture. A common file "arch.h" is used to include the
right file among arch-* based on the detected architecture. Projects
which are already split per architecture could simply rename these
files to $arch/arch.h and get rid of the common arch.h. For this
reason, include guards were placed into each arch-specific file.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/tools/include/nolibc/arch.h b/tools/include/nolibc/arch.h
new file mode 100644
index 000000000000..4c6992321b0d
--- /dev/null
+++ b/tools/include/nolibc/arch.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
+ */
+
+/* Below comes the architecture-specific code. For each architecture, we have
+ * the syscall declarations and the _start code definition. This is the only
+ * global part. On all architectures the kernel puts everything in the stack
+ * before jumping to _start just above us, without any return address (_start
+ * is not a function but an entry pint). So at the stack pointer we find argc.
+ * Then argv[] begins, and ends at the first NULL. Then we have envp which
+ * starts and ends with a NULL as well. So envp=argv+argc+1.
+ */
+
+#ifndef _NOLIBC_ARCH_H
+#define _NOLIBC_ARCH_H
+
+#if defined(__x86_64__)
+#include "arch-x86_64.h"
+#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
+#include "arch-i386.h"
+#elif defined(__ARM_EABI__)
+#include "arch-arm.h"
+#elif defined(__aarch64__)
+#include "arch-aarch64.h"
+#elif defined(__mips__) && defined(_ABIO32)
+#include "arch-mips.h"
+#elif defined(__riscv)
+#include "arch-riscv.h"
+#endif
+
+#endif /* _NOLIBC_ARCH_H */