frv: resurrect port somehow, totally untested

The FR-V port is really broken, and I have no emulator
or hardware for this platform. I tried to get some hardware
from RedHat, who made the FR-V port initially. Unfortunately
Fujitsi didn't agreed to sent me some of their unused spare
hardware lying @RedHat. As I invested some time to get stuff compiled,
I decided to add the code and may be anytime later I can gain
access to some emulator or hardware.

GDB simulator for FR-V doesn't support booting Linux AFAIK.

1 files changed, 121 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/frv/crt1.S b/libc/sysdeps/linux/frv/crt1.S
new file mode 100644
index 000000000..0827feae7
--- /dev/null
+++ b/libc/sysdeps/linux/frv/crt1.S
@@ -0,0 +1,121 @@
+/* Copyright (C) 1991, 1992, 2003, 2004 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+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
+Library General Public License for more details.
+
+In addition to the permissions in the GNU Lesser General Public
+License, the Free Software Foundation gives you unlimited
+permission to link the compiled version of this file with other
+programs, and to distribute those programs without any restriction
+coming from the use of this file.  (The GNU Lesser General Public
+License restrictions do apply in other respects; for example, they
+cover modification of the file, and distribution when not linked
+into another program.)
+
+You should have received a copy of the GNU Lesser General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, see <http://www.gnu.org/licenses/>.  */
+
+
+/*  Based on ../i386/crt0.S and newlib's libgloss/frv/crt0.S  */
+
+/*
+    When we enter this piece of code, the program stack looks like this:
+        argc            argument counter (integer)
+        argv[0]         program name (pointer)
+        argv[1...N]     program args (pointers)
+        argv[argc-1]    end of args (integer)
+	NULL
+        env[0...N]      environment variables (pointers)
+        NULL
+
+    Also, GR16 holds a pointer to a memory map.  */
+
+#include <features.h>
+
+	.text
+	.global _start
+	.type	_start,%function
+	.weak	_init
+	.weak	_fini
+	.type	__uClibc_main,%function
+
+_start:
+	/* Make sure the stack pointer is properly aligned.  Save the
+	   original value in gr21 such that we can get to arguments and
+	   such from there.  */
+	mov.p	sp, gr21
+	andi	sp, #-8, sp
+	/* At program start-up, gr16 contains a pointer to a memory
+	   map, that we use to relocate addresses.  */
+	call	.Lcall
+.Lcall:
+	movsg	lr, gr4
+	sethi.p	#gprelhi(.Lcall), gr5
+	setlo	#gprello(.Lcall), gr5
+	sub.p	gr4, gr5, gr4
+	/* gr4 now holds the _gp address.  */
+
+	mov	gr16, gr8
+	sethi.p #gprelhi(__ROFIXUP_LIST__), gr9
+	sethi	#gprelhi(__ROFIXUP_END__), gr10
+	setlo.p #gprello(__ROFIXUP_LIST__), gr9
+	setlo	#gprello(__ROFIXUP_END__), gr10
+	add.p	gr9, gr4, gr9
+	add	gr10, gr4, gr10
+	call	__self_reloc
+	mov.p	gr8, gr17
+	mov	gr8, gr15
+	/* gr17 now holds the self-relocated _GLOBAL_OFFSET_TABLE_
+	address, because the linker added its unrelocated address as
+	the last entry in the ROFIXUP list, and __self_reloc returns
+	the last entry, relocated.  */
+
+	/* Prepare arguments for uClibc main.  */
+	ld	@(gr21, gr0), gr8
+	slli	gr8, #2, gr10
+	add	gr21, gr10, gr10
+	addi.p	gr21, #4, gr9
+	addi	gr10, #8, gr10
+
+	/* Set up an invalid (NULL return address, NULL frame pointer)
+	   callers stack frame so anybody unrolling the stack knows where
+	   to stop */
+	mov	gr0, fp
+	movgs	gr0, lr
+
+#if (defined L_crt1 || defined L_Scrt1) && defined __UCLIBC_CTOR_DTOR__
+	/* Pass .init and .fini arguments to __uClibc_start_main().  */
+	sethi.p	#gotfuncdeschi(_init), gr11
+	sethi	#gotfuncdeschi(_fini), gr12
+	setlo.p	#gotfuncdesclo(_init), gr11
+	setlo	#gotfuncdesclo(_fini), gr12
+	ld.p	@(gr11, gr17), gr11
+	mov	gr17, gr15
+	ld.p	@(gr12, gr17), gr12
+	call	__uClibc_main
+#else
+	mov.p	gr17, gr15
+	call	__uClibc_main
+#endif
+
+	/* Crash if somehow `exit' returns anyways.  */
+	jmpl	@(gr0,gr0)
+.size _start,.-_start
+
+/* Define a symbol for the first piece of initialized data.  */
+	.data
+	.globl __data_start
+__data_start:
+	.long 0
+	.weak data_start
+	data_start = __data_start
+