/********************************************************************
* common/up_nommuhead.S
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name Gregory Nutt nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
********************************************************************/
/********************************************************************
* Included Files
********************************************************************/
#include <nuttx/config.h>
#include "up_internal.h"
#include "up_arch.h"
/********************************************************************
* Macros
********************************************************************/
/* This macro will modify r0, r1, r2 and r14 */
#ifdef CONFIG_DEBUG
.macro showprogress, code
mov r0, #\code
bl up_lowputc
.endm
#else
.macro showprogress, code
.endm
#endif
/********************************************************************
* OS Entry Point
********************************************************************/
/* We assume the bootloader has already initialized most of the h/w for
* us and that only leaves us having to do some os specific things
* below.
*/
.text
.global __start
.type __start, #function
__start:
/* First, setup initial processor mode */
mov r0, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT )
msr cpsr, r0
showprogress 'A'
/* Setup system stack (and get the BSS range) */
adr r0, LC0
ldmia r0, {r4, r5, sp}
/* Clear system BSS section */
mov r0, #0
1: cmp r4, r5
strcc r0, [r4], #4
bcc 1b
showprogress 'B'
/* Copy system .data sections to new home in RAM. */
#ifdef CONFIG_BOOT_FROM_FLASH
adr r3, LC2
ldmia r3, {r0, r1, r2}
1: ldmia r0!, {r3 - r10}
stmia r1!, {r3 - r10}
cmp r1, r2
blt 1b
#endif
/* Perform early serial initialization */
mov fp, #0
#ifdef CONFIG_USE_EARLYSERIALINIT
bl up_earlyserialinit
#endif
#ifdef CONFIG_DEBUG
mov r0, #'C'
bl up_putc
mov r0, #'\n'
bl up_putc
#endif
/* Initialize onboard LEDs */
#ifdef CONFIG_ARCH_LEDS
bl up_ledinit
#endif
/* Then jump to OS entry */
b os_start
/* Variables:
* _sbss is the start of the BSS region (see ld.script)
* _ebss is the end of the BSS regsion (see ld.script)
* The idle task stack starts at the end of BSS and is
* of size CONFIG_PROC_STACK_SIZE. The heap continues
* from there until the end of memory. See g_heapbase
* below.
*/
LC0: .long _sbss
.long _ebss
.long _ebss+CONFIG_PROC_STACK_SIZE-4
#ifdef CONFIG_BOOT_FROM_FLASH
LC2: .long _eronly /* Where .data defaults are stored in FLASH */
.long _sdata /* Where .data needs to reside in SDRAM */
.long _edata
#endif
.size __start, .-__start
/* This global variable is unsigned long g_heapbase and is
* exported from here only because of its coupling to LCO
* above.
*/
.data
.align 4
.globl g_heapbase
.type g_heapbase, object
g_heapbase:
.long _ebss+CONFIG_PROC_STACK_SIZE
.size g_heapbase, .-g_heapbase
.end
