Add support for the Analog Devices Blackfin mmuless processor

1 files changed, 68 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/bfin/crt0.S b/libc/sysdeps/linux/bfin/crt0.S
new file mode 100644
index 000000000..4ddfd16b9
--- /dev/null
+++ b/libc/sysdeps/linux/bfin/crt0.S
@@ -0,0 +1,68 @@
+/* Copyright (C) 1991, 1992 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+
+/* When we enter this piece of code, the user stack looks like this:
+*      argc            argument counter (integer)
+*      argv[0]         program name (pointer)
+*      argv[1...N]     program args (pointers)
+*      NULL
+*      env[0...N]      environment variables (pointers)
+*      NULL
+
+*   When we are done here, we want
+*	R0=argc
+*	R1=*argv[0]
+*	R2=*envp[0]
+*/
+
+.text
+.align 2
+.global _start;
+.type	_start,STT_FUNC;
+.global ___uClibc_main;
+.type	___uClibc_main,STT_FUNC;
+
+/* Stick in a dummy reference to main(), so that if an application
+ * is linking when the main() function is in a static library (.a)
+ * we can be sure that main() actually gets linked in */
+
+.type	_main,STT_FUNC;
+
+_start:
+
+/*	clear the frame pointer */
+	FP = 0;
+/*	Load register R0 (argc) from the stack to its final resting place */
+	P0 = SP;
+	R0 = [P0++];
+
+/*	Copy argv pointer into R1 -- which its final resting place */
+	R1 = P0;
+
+/*	Skip to the end of argv and put a pointer to the environment in R2 */
+	R2 = R0;
+	R2 <<= 2;
+	R2 += 4;
+	R2 = R1+R2;
+
+/*	Ok, now run uClibc's main() -- shouldn't return */
+	sp += -12;
+	jump.l	___uClibc_main;
+