215 lines
4.7 KiB
ArmAsm
215 lines
4.7 KiB
ArmAsm
/*
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* File : start.S
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* This file is part of RT-Thread RTOS
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* COPYRIGHT (C) 2006, RT-Thread Development Team
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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://openlab.rt-thread.com/license/LICENSE
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*
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* Change Logs:
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* Date Author Notes
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* 2008-12-11 XuXinming first version
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*/
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/**
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* @addtogroup LPC2478
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*/
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/*@{*/
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#define WDMOD (0xE0000000 + 0x00)
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#define VICIntEnClr (0xFFFFF000 + 0x014)
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#define VICVectAddr (0xFFFFF000 + 0xF00)
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#define VICIntSelect (0xFFFFF000 + 0x00C)
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#define PLLCFG (0xE01FC000 + 0x084)
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#define PLLCON (0xE01FC000 + 0x080)
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#define PLLFEED (0xE01FC000 + 0x08C)
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#define PLLSTAT (0xE01FC000 + 0x088)
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#define CCLKCFG (0xE01FC000 + 0x104)
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#define MEMMAP (0xE01FC000 + 0x040)
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#define SCS (0xE01FC000 + 0x1A0)
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#define CLKSRCSEL (0xE01FC000 + 0x10C)
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#define MAMCR (0xE01FC000 + 0x000)
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#define MAMTIM (0xE01FC000 + 0x004)
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/*.section .init, "ax"*/
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.section .vectors
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.code 32
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.globl _start
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_start:
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b reset
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ldr pc, _vector_undef
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ldr pc, _vector_swi
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ldr pc, _vector_pabt
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ldr pc, _vector_dabt
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ldr pc, _vector_resv
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ldr pc, _vector_irq
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ldr pc, _vector_fiq
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_vector_undef: .word vector_undef
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_vector_swi: .word vector_swi
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_vector_pabt: .word vector_pabt
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_vector_dabt: .word vector_dabt
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_vector_resv: .word vector_resv
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_vector_irq: .word vector_irq
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_vector_fiq: .word vector_fiq
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.text
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.code 32
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/* the system entry */
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reset:
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/* enter svc mode */
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msr cpsr_c, #SVCMODE|NOINT
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/*watch dog disable */
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ldr r0,=WDMOD
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ldr r1,=0x0
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str r1,[r0]
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/* all interrupt disable */
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ldr r0,=VICIntEnClr
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ldr r1,=0xffffffff
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str r1,[r0]
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ldr r1, =VICVectAddr
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ldr r0, =0x00
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str r0, [r1]
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ldr r1, =VICIntSelect
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ldr r0, =0x00
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str r0, [r1]
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/* setup stack */
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bl stack_setup
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_rtthread_startup: .word rtthread_startup
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.equ USERMODE, 0x10
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.equ FIQMODE, 0x11
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.equ IRQMODE, 0x12
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.equ SVCMODE, 0x13
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.equ ABORTMODE, 0x17
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.equ UNDEFMODE, 0x1b
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.equ MODEMASK, 0x1f
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.equ NOINT, 0xc0
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/* exception handlers */
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vector_undef: bl rt_hw_trap_udef
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vector_swi: bl rt_hw_trap_swi
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vector_pabt: bl rt_hw_trap_pabt
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vector_dabt: bl rt_hw_trap_dabt
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vector_resv: bl rt_hw_trap_resv
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.globl rt_interrupt_enter
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.globl rt_interrupt_leave
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.globl rt_thread_switch_interrput_flag
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.globl rt_interrupt_from_thread
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.globl rt_interrupt_to_thread
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vector_irq:
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stmfd sp!, {r0-r12,lr}
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bl rt_interrupt_enter
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bl rt_hw_trap_irq
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bl rt_interrupt_leave
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/* if rt_thread_switch_interrput_flag set, jump to _interrupt_thread_switch and don't return */
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ldr r0, =rt_thread_switch_interrput_flag
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ldr r1, [r0]
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cmp r1, #1
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beq _interrupt_thread_switch
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ldmfd sp!, {r0-r12,lr}
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subs pc, lr, #4
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.align 5
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vector_fiq:
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stmfd sp!,{r0-r7,lr}
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bl rt_hw_trap_fiq
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ldmfd sp!,{r0-r7,lr}
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subs pc,lr,#4
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_interrupt_thread_switch:
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mov r1, #0 @ clear rt_thread_switch_interrput_flag
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str r1, [r0]
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ldmfd sp!, {r0-r12,lr} @ reload saved registers
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stmfd sp!, {r0-r3} @ save r0-r3
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mov r1, sp
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add sp, sp, #16 @ restore sp
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sub r2, lr, #4 @ save old task's pc to r2
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mrs r3, spsr @ disable interrupt
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orr r0, r3, #NOINT
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msr spsr_c, r0
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ldr r0, =.+8 @ switch to interrupted task's stack
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movs pc, r0
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stmfd sp!, {r2} @ push old task's pc
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stmfd sp!, {r4-r12,lr} @ push old task's lr,r12-r4
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mov r4, r1 @ Special optimised code below
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mov r5, r3
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ldmfd r4!, {r0-r3}
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stmfd sp!, {r0-r3} @ push old task's r3-r0
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stmfd sp!, {r5} @ push old task's psr
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mrs r4, spsr
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stmfd sp!, {r4} @ push old task's spsr
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ldr r4, =rt_interrupt_from_thread
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ldr r5, [r4]
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str sp, [r5] @ store sp in preempted tasks's TCB
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ldr r6, =rt_interrupt_to_thread
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ldr r6, [r6]
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ldr sp, [r6] @ get new task's stack pointer
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ldmfd sp!, {r4} @ pop new task's spsr
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msr SPSR_cxsf, r4
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ldmfd sp!, {r4} @ pop new task's psr
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msr CPSR_cxsf, r4
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ldmfd sp!, {r0-r12,lr,pc} @ pop new task's r0-r12,lr & pc
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/* each mode stack memory */
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stack_setup:
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mrs r0, cpsr
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bic r0, r0, #MODEMASK
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orr r1, r0, #UNDEFMODE|NOINT
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msr cpsr_cxsf, r1 @ undef mode
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ldr sp, =__UndStack_end
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mrs r0, cpsr
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bic r0, r0, #MODEMASK
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orr r1,r0,#ABORTMODE|NOINT
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msr cpsr_cxsf,r1 @ abort mode
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ldr sp,=__ABTStack_end
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mrs r0, cpsr
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bic r0, r0, #MODEMASK
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orr r1,r0,#IRQMODE|NOINT
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msr cpsr_cxsf,r1 @ IRQ mode
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ldr sp,=__IRQStack_end
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mrs r0, cpsr
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bic r0, r0, #MODEMASK
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orr r1,r0,#FIQMODE|NOINT
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msr cpsr_cxsf,r1 @ FIQ mode
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ldr sp,=__FIQStack_end
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mrs r0, cpsr
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bic r0, r0, #MODEMASK
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orr r1,r0,#SVCMODE|NOINT
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msr cpsr_cxsf,r1 @ SVC mode
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ldr sp,=__SVCStack_end
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/* USER mode is not initialized. */
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mrs r0, cpsr
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bic r0, r0, #MODEMASK|0x80 //IRQ enable and FIQ disable
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orr r1,r0,#USERMODE
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msr cpsr_cxsf,r1 @ usr mode
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ldr sp,=__USRStack_end
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ldr pc, _rtthread_startup
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