/**************************************************************************** * arch/avr32/src/avr32/up_nommuhead.S * * Copyright (C) 2010 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 NuttX 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 #include #include "up_internal.h" #include "up_arch.h" /**************************************************************************** * External Symbols ****************************************************************************/ .file "up_nommuhead.S" .global _sbss /* Start of .bss. Defined by ld.script */ .global _ebss /* End of .bss. Defined by ld.script */ #ifdef CONFIG_BOOT_RUNFROMFLASH .global _sdata /* Start of .data section in RAM */ .global _edata /* End of .data section in RAM */ .global _eronly /* Start of .data section in FLASH */ #endif .global up_lowinit /* Perform low level initialization */ .global os_start /* NuttX entry point */ .global vectortab /* Vector base address */ /**************************************************************************** * Macros ****************************************************************************/ /**************************************************************************** * OS Entry Point ****************************************************************************/ /* The following entry point must be linked to execute at 0x80000000 if it * is to execute upon reset. */ .text .global __start .type __start, @function __start: /* Set the IDLE thread stack pointer. This stack will be used * through NuttX initialization and will, eventually, be inherited * by the IDLE thread when threading is enabled. */ lddpc sp, .Lstackbase /* Set up the vector base address so interrupts can be enabled. */ lda.w r0, vectortab mtsr AVR32_EVBA, r0 /* Enable exception processing */ csrf AVR32_SR_EM_SHIFT /* Clear system BSS section */ lda.w r0, _sbss /* R =Start of .bss */ lda.w r1, _ebss /* r1=End of .bss */ mov r2, 0 /* Value to write to .bss */ rjmp 2f /* Start at the bottom of the loop */ 1: st.d r0++, r2 /* Zero .bss */ 2: cp r0, r1 /* Finished? */ brlo 1b /* No... keep looping */ /* Copy system .data sections to new home in RAM. */ #ifdef CONFIG_BOOT_RUNFROMFLASH lda.w r0, _sdata /* r0=Start of .data section in RAM */ lda.w r1, _edata /* r1=End of .data section in RAM */ lda.w r2, _eronly /* r2=Start of .data in FLASH */ rjmp 4f /* Start at the bottom of the loop */ 3: ld.d r4, r2++ /* Fetch the next data value */ st.d r0++, r4 /* Write it to the .data section */ 4: cp r0, r1 /* Finished? */ brlo 3b /* No... keep looping */ #endif /* Clear the frame pointer and link register since this is the outermost * frame. */ mov r7, 0 mov lr, 0 /* Perform low-level initialization */ mcall .Lup_lowinit /* Then jump to OS entry (will not return) */ lda.w pc, os_start .Lstackbase: .word _ebss+CONFIG_IDLETHREAD_STACKSIZE-4 .Lup_lowinit: .word up_lowinit .size __start, .-__start /* This global variable is unsigned long g_idle_topstack and is * exported from here only because of its coupling to other * uses of _ebss in this file */ .data .align 4 .globl g_idle_topstack .type g_idle_topstack, object g_idle_topstack: .long _ebss+CONFIG_IDLETHREAD_STACKSIZE .size g_idle_topstack, .-g_idle_topstack .end