From c4c192b0273454e81cd9cb91441c747abaabf6ec Mon Sep 17 00:00:00 2001
From: gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4>
Date: Mon, 9 Feb 2009 22:01:42 +0000
Subject: git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@750
 35acf78f-673a-0410-8e92-d51de3d6d3f4

---
 ports/ARM7/crt0.s   | 63 +++++++++++++++++++----------------------------------
 ports/ARM7/port.dox | 49 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+), 40 deletions(-)

(limited to 'ports/ARM7')

diff --git a/ports/ARM7/crt0.s b/ports/ARM7/crt0.s
index d066ee478..91d07935b 100644
--- a/ports/ARM7/crt0.s
+++ b/ports/ARM7/crt0.s
@@ -119,56 +119,33 @@ bssloop:
         /*
          * Late initialization.
          */
-#ifndef THUMB_NO_INTERWORKING
+#ifdef THUMB_NO_INTERWORKING
+        add     r0, pc, #1
+        bx      r0
+.code 16
         bl      hwinit1
-        /*
-         * main(0, NULL).
-         */
         mov     r0, #0
         mov     r1, r0
         bl      main
-        bl      port_halt
+        ldr     r1, =MainExitHandler
+        bx      r1
+.code 32
 #else
-        add     r0, pc, #1
-        bx      r0
-.code 16
         bl      hwinit1
         mov     r0, #0
         mov     r1, r0
         bl      main
-        bl      port_halt
-.code 32
+        b       MainExitHandler
 #endif
 
 /*
- * Default exceptions handlers. The handlers are declared weak in order to be
- * replaced by the real handling code.
+ * Default main function exit handler.
  */
-.weak UndHandler
-.globl UndHandler
-UndHandler:
-
-.weak SwiHandler
-.globl SwiHandler
-SwiHandler:
-
-.weak PrefetchHandler
-.globl PrefetchHandler
-PrefetchHandler:
-
-.weak AbortHandler
-.globl AbortHandler
-AbortHandler:
-
-.weak FiqHandler
-.globl FiqHandler
-FiqHandler:
+.weak MainExitHandler
+.globl MainExitHandler
+MainExitHandler:
 
-.loop: b        .loop
-
-#ifdef THUMB_NO_INTERWORKING
-.code 16
-#endif
+.loop:  b       .loop
 
 /*
  * Default early initialization code. It is declared weak in order to be
@@ -176,11 +153,14 @@ FiqHandler:
  * Early initialization is performed just after reset before BSS and DATA
  * segments initialization.
  */
-.global hwinit0
-.weak hwinit0
+#ifdef THUMB_NO_INTERWORKING
 .thumb_func
+.code 16
+#endif
+.weak hwinit0
 hwinit0:
         bx      lr
+.code 32
 
 /*
  * Default late initialization code. It is declared weak in order to be
@@ -188,11 +168,14 @@ hwinit0:
  * Late initialization is performed after BSS and DATA segments initialization
  * and before invoking the main() function.
  */
-.global hwinit1
-.weak hwinit1
+#ifdef THUMB_NO_INTERWORKING
 .thumb_func
+.code 16
+#endif
+.weak hwinit1
 hwinit1:
         bx      lr
+.code 32
 
 /** @endcond */
 /** @} */
diff --git a/ports/ARM7/port.dox b/ports/ARM7/port.dox
index 28ce34ef6..016d2aceb 100644
--- a/ports/ARM7/port.dox
+++ b/ports/ARM7/port.dox
@@ -138,3 +138,52 @@
  * @file ports/ARM7/chcore.c Port related code.
  */
 /** @} */
+
+/**
+ * @defgroup ARM7_STARTUP Startup Support
+ * @{
+ * @brief ARM7 startup code support.
+ * @details ChibiOS/RT provides its own generic startup file for the ARM7 port.
+ * Of course it is not mandatory to use it but care should be taken about the
+ * startup phase details.
+ *
+ * <h2>Startup Process</h2>
+ * The startup process, as implemented, is the following:
+ * -# Initialize the various stacks assigning them the sizes defined in the
+ *    linker script (usually named @p ch.ld). Stack areas are allocated from
+ *    the highest RAM location downward.
+ * -# The ARM state is switched to System with both IRQ and FIQ sources
+ *    disabled.
+ * -# An early initialization routine @p hwinit0 is invoked, if the symbol not
+ *    defined then an empty default routine is executed (weak symbol).
+ * -# DATA and BSS segments are initialized.
+ * -# A late initialization routine @p hwinit1 is invoked, if the symbol not
+ *    defined then an empty default routine is executed (weak symbol).<br>
+ *    This late initialization function is also the proper place for a
+ *    @a bootloader, if your application requires one.
+ * -# The @p main() function is invoked with the parameters @p argc and @p argv
+ *    set to zero.
+ * -# Should the @p main() function return a branch is performed to the weak
+ *    symbol MainExitHandler. The default code is an endless empty loop.
+ * .
+ * <h2>Expected linker symbols</h2>
+ * The startup code starts at the symbol @p ResetHandler and expects the
+ * following symbols to be defined in the linker script:
+ * - @p __ram_end__ RAM end location +1.
+ * - @p __und_stack_size__ Undefined Instruction stack size.
+ * - @p __abt_stack_size__ Memory Abort stack size.
+ * - @p __fiq_stack_size__ FIQ service stack size.
+ * - @p __irq_stack_size__ IRQ service stack size.
+ * - @p __svc_stack_size__ SVC service stack size.
+ * - @p __sys_stack_size__ System/User stack size. This is the stack used
+ *      by the @p main() function.
+ * - @p _textdata address of the data segment source read only data.
+ * - @p _data data segment start location.
+ * - @p _edata data segment end location +1.
+ * - @p _bss_start BSS start location.
+ * - @p _bss_end BSS end location +1.
+ * .
+ * @ingroup ARM7
+ * @file ports/ARM7/crt0.s Startup code.
+ */
+/** @} */
-- 
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