forked from Imagelibrary/rtems
ff081aee72
Rename * _Configuration_Interrupt_stack_area_begin in _ISR_Stack_area_begin, * _Configuration_Interrupt_stack_area_end in _ISR_Stack_area_end, and * _Configuration_Interrupt_stack_size in _ISR_Stack_size. Move definitions to <rtems/score/isr.h>. The new names are considerable shorter and in the right namespace. Update #3459.
123 lines
3.0 KiB
ArmAsm
123 lines
3.0 KiB
ArmAsm
/*
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* start.S -- startup file for Cogent CSB350 Au1100 based board
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*
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* Copyright (c) 2005 by Cogent Computer Systems
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* Written by Jay Monkman <jtm@lopingdog.com>
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.org/license/LICENSE.
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*
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*/
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#include <rtems/asm.h>
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#include <bsp/regs.h>
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.text
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.align 2
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/* Without the following nop, GDB thinks _start is a data variable.
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* This is probably a bug in GDB in handling a symbol that is at the
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* start of the .text section.
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*/
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nop
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.globl _start
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.ent _start
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_start:
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.set noreorder
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/* Get the address of start into $5 in a position independent
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* fashion. This lets us know whether we have been relocated or not.
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*/
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$LF1 = . + 8
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bal $LF1
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nop
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_branch:
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move $5, $31 /* $5 == where are we */
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li $6, 0x8800000c /* $6 == where we want to be */
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li v0, SR_CU1|SR_PE|SR_FR|SR_KX|SR_SX|SR_UX
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mtc0 v0, C0_SR
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mtc0 zero, C0_CAUSE
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1:
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li v0, SR_PE|SR_FR|SR_KX|SR_SX|SR_UX
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mtc0 v0, C0_SR
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2:
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/* Fix high bits, if any, of the PC so that exception handling
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doesn't get confused. */
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la v0, 3f
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jr v0
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nop
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3:
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la gp, _gp /* set the global data pointer */
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.end _start
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/*
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* zero out the bss section.
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*/
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.globl zerobss
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.ent zerobss
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zerobss:
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la v0, _fbss
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la v1, _end
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3:
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sw zero,0(v0)
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bltu v0,v1,3b
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addiu v0,v0,4 /* executed in delay slot */
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la t0, _ISR_Stack_area_end /* initialize stack so we */
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/* We must subtract 24 bytes for the 3 8 byte arguments to main, in
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case main wants to write them back to the stack. The caller is
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supposed to allocate stack space for parameters in registers in
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the old MIPS ABIs. We must do this even though we aren't passing
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arguments, because main might be declared to have them.
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Some ports need a larger alignment for the stack, so we subtract
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32, which satisifes the stack for the arguments and keeps the
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stack pointer better aligned. */
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subu t0,t0,32
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move sp,t0 /* set stack pointer */
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.end zerobss
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.globl exit .text
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.globl init
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.ent init
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init:
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move a0,zero /* set command line to 0 */
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jal boot_card /* call the program start function */
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nop
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/* fall through to the "exit" routine */
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jal _sys_exit /* call libc exit to run the G++ */
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/* destructors */
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move a0,v0 /* pass through the exit code */
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.end init
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/*
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* _sys_exit -- Exit from the application. Normally we cause a user trap
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* to return to the ROM monitor for another run. NOTE: This is
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* the only other routine we provide in the crt0.o object, since
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* it may be tied to the "_start" routine. It also allows
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* executables that contain a complete world to be linked with
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* just the crt0.o object.
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*/
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.globl _sys_exit
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.ent _sys_exit
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_sys_exit:
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7:
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#ifdef GCRT0
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jal _mcleanup
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nop
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#endif
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/* break inst. can cope with 0xfffff, but GAS limits the range: */
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break 1023
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nop
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b 7b /* but loop back just in-case */
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nop
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.end _sys_exit
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/* EOF crt0.S */
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