From 7b10ef9a7c55764d1b6815fd0871cb51ff0205f9 Mon Sep 17 00:00:00 2001
From: Marcoen Hirschberg <marcoen@gmail.com>
Date: Fri, 27 Jun 2008 23:24:34 +0000
Subject: initial Meizu M6SL port (take 2)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17819 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/target/arm/s5l8700/crt0.S | 117 +++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 firmware/target/arm/s5l8700/crt0.S

(limited to 'firmware/target/arm/s5l8700/crt0.S')

diff --git a/firmware/target/arm/s5l8700/crt0.S b/firmware/target/arm/s5l8700/crt0.S
new file mode 100644
index 0000000000..3ecabdeaef
--- /dev/null
+++ b/firmware/target/arm/s5l8700/crt0.S
@@ -0,0 +1,117 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2008 by Marcoen Hirschberg
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "config.h"
+#include "cpu.h"
+
+    .section .init.text,"ax",%progbits
+
+    .global    start
+start:
+    /* Exception vectors */
+    b       newstart
+    b       undef_instr_handler
+    b       software_int_handler
+    b       prefetch_abort_handler
+    b       data_abort_handler
+    b       reserved_handler
+    b       irq_handler
+    b       fiq_handler
+    .word 0x43554644 /* DFUC */
+
+newstart:
+#if 0
+    msr     cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ/FIQ */
+
+    /* Initialise bss section to zero */
+    ldr     r2, =_edata
+    ldr     r3, =_end
+    mov     r4, #0
+1:
+    cmp     r3, r2
+    strhi   r4, [r2], #4
+    bhi     1b
+    
+    /* Set up some stack and munge it with 0xdeadbeef */
+    ldr     sp, =stackend
+    ldr     r2, =stackbegin
+    ldr     r3, =0xdeadbeef
+1:
+    cmp     sp, r2
+    strhi   r3, [r2], #4
+    bhi     1b
+    
+    /* Set up stack for IRQ mode */ 
+    msr     cpsr_c, #0xd2
+    ldr     sp, =irq_stack
+
+    /* Set up stack for FIQ mode */ 
+    msr     cpsr_c, #0xd1
+    ldr     sp, =fiq_stack
+
+    /* Let abort and undefined modes use IRQ stack */
+    msr     cpsr_c, #0xd7
+    ldr     sp, =irq_stack
+    msr     cpsr_c, #0xdb
+    ldr     sp, =irq_stack
+
+    /* Switch back to supervisor mode */
+    msr     cpsr_c, #0xd3
+#endif
+   bl      main
+
+
+    .text
+/*    .global UIE*/
+
+/* All illegal exceptions call into UIE with exception address as first
+ * parameter. This is calculated differently depending on which exception
+ * we're in. Second parameter is exception number, used for a string lookup
+ * in UIE. */
+undef_instr_handler:
+    mov    r0, lr
+    mov    r1, #0
+    b      UIE
+
+/* We run supervisor mode most of the time, and should never see a software
+ * exception being thrown. Perhaps make it illegal and call UIE? */
+software_int_handler:
+reserved_handler:
+    movs   pc, lr
+
+prefetch_abort_handler:
+    sub    r0, lr, #4
+    mov    r1, #1
+    b      UIE
+
+data_abort_handler:
+    sub    r0, lr, #8 
+    mov    r1, #2
+    b      UIE
+
+/* 256 words of IRQ stack */
+    .space 256*4
+irq_stack:
+
+/* 256 words of FIQ stack */
+    .space 256*4
+fiq_stack:
+
+end:
+    /*.word 0xA5A5A5A5
+    .word 0x5A5A5A5A*/
-- 
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