coldfire: Implement HAVE_INIT_ATTR magic

This reclaims ~6kB of ram.

Change-Id: Iafdc661b1cf4445669c08c79205043792b8d14c3
Reviewed-on: http://gerrit.rockbox.org/718
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>

firmware/export/config.h

@@ -982,7 +982,7 @@ Lyre prototype 1 */
 
 #if (defined(CPU_PP) || (CONFIG_CPU == AS3525) || (CONFIG_CPU == AS3525v2) || \
     (CONFIG_CPU == IMX31L) || (CONFIG_CPU == IMX233) || \
-    (CONFIG_CPU == RK27XX)) \
+    (CONFIG_CPU == RK27XX) || defined(CPU_COLDFIRE)) \
     && (CONFIG_PLATFORM & PLATFORM_NATIVE) && !defined(BOOTLOADER)
 /* Functions that have INIT_ATTR attached are NOT guaranteed to survive after
  * root_menu() has been called. Their code may be overwritten by other data or

firmware/target/coldfire/app.lds

@@ -20,6 +20,11 @@ STARTUP(target/coldfire/crt0.o)
 
 /* End of the audio buffer, where the codec buffer starts */
 #define ENDAUDIOADDR  (DRAMORIG + DRAMSIZE)
+#define CODECORIG ENDAUDIOADDR
+
+/* .init is copied to codec buffer */
+#define INITORIG CODECORIG
+#define INITSIZE CODECSIZE
 
 /* Where the codec buffer ends, and the plugin buffer starts */
 #define ENDADDR (ENDAUDIOADDR + CODECSIZE)
@@ -28,6 +33,7 @@ MEMORY
 {
     DRAM : ORIGIN = DRAMORIG, LENGTH = DRAMSIZE
     IRAM : ORIGIN = IRAMORIG, LENGTH = IRAMSIZE
+    INIT : ORIGIN = INITORIG, LENGTH = INITSIZE
 }
 
 SECTIONS
@@ -45,7 +51,7 @@ SECTIONS
     .text :
     {
         . = ALIGN(0x200);
-        *(.init.text)
+        KEEP(*(.startup*));
         *(.text*)
         . = ALIGN(0x4);
     } > DRAM
@@ -90,6 +96,15 @@ SECTIONS
     _iramcopy = LOADADDR(.iram);
     _noloaddram = LOADADDR(.iram);
 
+    .init :
+    {
+        _initstart = .;
+        *(.init*)
+        *(.initdata*)
+        _initend = .;
+    } > INIT AT > DRAM
+    _initcopy = LOADADDR(.init);
+
     .ibss (NOLOAD) :
     {
         _iedata = .;

firmware/target/coldfire/crt0.S

@@ -21,7 +21,7 @@
 #include "config.h"
 #include "cpu.h"
 
-    .section .init.text,"ax",@progbits
+    .section .startup,"ax",@progbits
 
     .global    start
 start:
@@ -290,6 +290,17 @@ start:
     /* .iram copy is done first since it is reclaimed for other
      * uninitialized sections */
 
+    /* copy .init section */
+    lea     _initcopy,%a2
+    lea     _initstart,%a3
+    lea     _initend,%a4
+    bra.b   .initstart
+.initloop:
+    move.l  (%a2)+,(%a3)+
+.initstart:
+    cmp.l   %a3,%a4
+    bhi.b   .initloop
+
     /* copy the .iram section */
     lea     _iramcopy,%a2
     lea     _iramstart,%a3