From e130b681c43ee2215512ffcf6cadcbc4487e96e6 Mon Sep 17 00:00:00 2001
From: Carmelo Amoroso <carmelo.amoroso@st.com>
Date: Fri, 16 Nov 2007 14:26:46 +0000
Subject: Added AVR32 support to uClibc. Signed-off-by: Hans-Christian Egtvedt
 <hcegtvedt@atmel.com>

---
 libc/sysdeps/linux/avr32/crt1.S | 97 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 libc/sysdeps/linux/avr32/crt1.S

(limited to 'libc/sysdeps/linux/avr32/crt1.S')

diff --git a/libc/sysdeps/linux/avr32/crt1.S b/libc/sysdeps/linux/avr32/crt1.S
new file mode 100644
index 000000000..0f0a2e87d
--- /dev/null
+++ b/libc/sysdeps/linux/avr32/crt1.S
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2004-2007 Atmel Corporation
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License.  See the file "COPYING.LIB" in the main directory of this
+ * archive for more details.
+ *
+ * When we enter _start, the stack looks like this:
+ *     argc            argument counter
+ *     argv[0]         pointer to program name
+ *     argv[1..argc-1] pointers to program args
+ *     NULL
+ *     env[0..N]       pointers to environment variables
+ *     NULL
+ *
+ * r12 contains a function pointer to be registered with `atexit'.
+ * This is how the dynamic linker arranges to have DT_FINI functions
+ * called for shared libraries that have been loaded before this
+ * code runs.
+ *
+ * We're going to call the following function:
+ * __uClibc_main(int (*main)(int, char **, char **), int argc,
+ *              char **argv, void (*app_init)(void), void (*app_fini)(void),
+ *              void (*rtld_fini)(void), void *stack_end)
+ *
+ * So we need to set up things as follows:
+ *     r12 = address of main
+ *     r11 = argc
+ *     r10 = &argv[0]
+ *     r9  = address of _init
+ *     r8  = address of _fini
+ *     sp[0] = whatever we got passed in r12
+ */
+
+#include <features.h>
+
+       .text
+       .global _start
+       .type   _start, @function
+_start:
+       /* Clear the frame pointer and link register since this is the outermost frame.  */
+       mov     r7, 0
+       mov     lr, 0
+
+       ld.w    r11, sp++               /* argc         */
+       mov     r10, sp                 /* &argv[0]     */
+
+       st.w    --sp, r10               /* stack_end */
+       st.w    --sp, r12               /* rtld_fini */
+
+#ifdef __PIC__
+       lddpc   r6, .L_GOT
+.L_RGOT:
+       rsub    r6, pc
+       lda.w   r9, _init
+       lda.w   r8, _fini
+       lda.w   r12, main
+
+       /* Ok, now run uClibc's main() -- should not return */
+       call    __uClibc_main
+
+       .align  2
+.L_GOT:
+       .long   .L_RGOT - _GLOBAL_OFFSET_TABLE_
+#else
+       lddpc   r9, __init_addr         /* app_init */
+       lddpc   r8, __fini_addr         /* app_fini */
+       lddpc   r12, __main_addr        /* main */
+
+       /* Ok, now run uClibc's main() -- should not return */
+       lddpc   pc, ___uClibc_main_addr
+
+       .align  2
+__init_addr:
+       .long   _init
+__fini_addr:
+       .long   _fini
+__main_addr:
+       .long   main
+___uClibc_main_addr:
+       .long   __uClibc_main
+#endif
+       .size   _start, . - _start
+
+       /*
+        * The LSB says we need this.
+        */
+       .section ".note.ABI-tag", "a"
+       .align  4
+       .long   2f - 1f         /* namesz */
+       .long   4f - 3f         /* descsz */
+       .long   1               /* type   */
+1:     .asciz  "GNU"           /* name */
+2:     .align  4
+3:     .long   0               /* Linux executable */
+       .long   2,6,0           /* Earliest compatible kernel */
+4:     .align  4
-- 
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