kvx: add support for kvx arch to uClibc-ng

This commit adds support for Kalray VLIW family (kvx)

Kalray kv3 core is embedded in Kalray Coolidge SoC. This core which is the
third of the KV family has the following features:

    32/64 bits execution mode
    6-issue VLIW architecture
    64 x 64bits general purpose registers
    SIMD instructions
    little-endian

In order to build a usable toolchain, build scripts are provided at the
following address: https://github.com/kalray/build-scripts.

Kalray uses FOSS which is available at https://github.com/kalray
This includes Linux kernel, uClibc-ng, gcc, binutils, etc.

Signed-off-by: Clément Léger <cleger@kalray.eu>
Signed-off-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
Signed-off-by: Laurent Thevenoux <lthevenoux@kalray.eu>
Signed-off-by: Marc Poulhies <mpoulhies@kalray.eu>
Signed-off-by: Marius Gligor <mgligor@kalray.eu>
Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>

1 files changed, 104 insertions, 0 deletions

diff --git a/ldso/ldso/kvx/dl-startup.h b/ldso/ldso/kvx/dl-startup.h
new file mode 100644
index 000000000..9784c2345
--- /dev/null
+++ b/ldso/ldso/kvx/dl-startup.h
@@ -0,0 +1,104 @@
+/*
+ * Architecture specific code used by dl-startup.c
+ * Copyright (C) 2016 Waldemar Brodkorb <wbx@uclibc-ng.org>
+ * Copyright (C) 2018 Kalray Inc.
+ *
+ * Ported from GNU libc
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Copyright (C) 1995-2016 Free Software Foundation, Inc.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <features.h>
+
+/* This is the first bit of code, ever, executed in user space of a dynamically
+ * linked ELF.
+ * The kernel jumps on this with the following stack layout:
+ * 	argc            argument counter (integer)
+ *	argv[0]         program name (pointer)
+ *	argv[1..argc-1] program args (pointers)
+ * 	NULL
+ *	env[0...N]      environment variables (pointers)
+ *	NULL
+ *	auxvt[0...N]   Auxiliary Vector Table elements (mixed types)
+ *
+ * We should call _dl_start($sp) (the argument should point to the previously
+ * described memory layout).
+ *
+ * Next we should skip N arguments (N == _dl_skip_args).
+ * Those correspond to the arguments which are consumed by the dynamic loader
+ * if it is called directly as a program, which is possible when
+ * __LDSO_STANDALONE_SUPPORT__ is defined.
+ *
+ * We eventually end up calling the main executable's _start (from ctr1.S).
+ * The address of this _start is returned by _dl_start (in $r0).
+ *
+ * We should call this with one argument (in $r0): the address of _dl_fini()
+ */
+__asm__("\
+.text							\n\
+.globl _start						\n\
+.type _start, %function					\n\
+_start:							\n\
+	copyd $r0 = $sp					\n\
+	copyd $r18 = $sp				\n\
+	andd $sp = $sp, -32				\n\
+	call _dl_start					\n\
+	;;						\n\
+.globl _dl_start_user					\n\
+.type _dl_start_user, %function				\n\
+_dl_start_user:						\n\
+	pcrel $r1 = @gotaddr() 				\n\
+	copyd $r5 = $r0					\n\
+	copyd $sp = $r18				\n\
+	;;						\n\
+	ld $r2 = @gotoff(_dl_skip_args)[$r1]		\n\
+	addd $r0 = $r1, @gotoff(_dl_fini) 		\n\
+	;;						\n\
+	lwz $r3 = 0[$sp]				\n\
+	;;						\n\
+	sbfw $r4 = $r2, $r3				\n\
+	addx8d $sp = $r2, $sp				\n\
+	;;						\n\
+	sd 0[$sp] = $r4					\n\
+	icall $r5					\n\
+	;;						\n\
+");
+
+/* Get a pointer to the argv array.  On many platforms this can be just
+ * the address of the first argument, on other platforms we need to
+ * do something a little more subtle here.  */
+#define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long*)ARGS)+1)
+
+/* Handle relocation of the symbols in the dynamic loader. */
+static __always_inline
+void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, ElfW(Addr) *reloc_addr,
+	ElfW(Addr) symbol_addr, ElfW(Addr) load_addr, ElfW(Sym) *sym)
+{
+	switch (ELF_R_TYPE(rpnt->r_info)) {
+		case R_KVX_NONE:
+			break;
+		case R_KVX_JMP_SLOT:
+		 	*reloc_addr = symbol_addr + rpnt->r_addend;
+		 	break;
+		case R_KVX_RELATIVE:
+			*reloc_addr = load_addr + rpnt->r_addend;
+			break;
+		default:
+			_dl_exit(1);
+	}
+}