316 lines
10 KiB
ArmAsm
316 lines
10 KiB
ArmAsm
|
;/*
|
||
|
; * File : start_rvds.S
|
||
|
; * This file is part of RT-Thread RTOS
|
||
|
; * COPYRIGHT (C) 2006, RT-Thread Development Team
|
||
|
; *
|
||
|
; * The license and distribution terms for this file may be
|
||
|
; * found in the file LICENSE in this distribution or at
|
||
|
; * http://www.rt-thread.org/license/LICENSE
|
||
|
; *
|
||
|
; * Change Logs:
|
||
|
; * Date Author Notes
|
||
|
; * 2011-08-14 weety first version
|
||
|
; */
|
||
|
|
||
|
|
||
|
; Standard definitions of Mode bits and Interrupt (I & F) flags in PSRs
|
||
|
|
||
|
Mode_USR EQU 0x10
|
||
|
Mode_FIQ EQU 0x11
|
||
|
Mode_IRQ EQU 0x12
|
||
|
Mode_SVC EQU 0x13
|
||
|
Mode_ABT EQU 0x17
|
||
|
Mode_UND EQU 0x1B
|
||
|
Mode_SYS EQU 0x1F
|
||
|
|
||
|
SVCMODE EQU 0x13
|
||
|
MODEMASK EQU 0x1f
|
||
|
|
||
|
I_Bit EQU 0x80 ; when I bit is set, IRQ is disabled
|
||
|
F_Bit EQU 0x40 ; when F bit is set, FIQ is disabled
|
||
|
|
||
|
|
||
|
;----------------------- Stack and Heap Definitions ----------------------------
|
||
|
|
||
|
;// <h> Stack Configuration (Stack Sizes in Bytes)
|
||
|
;// <o0> Undefined Mode <0x0-0xFFFFFFFF:8>
|
||
|
;// <o1> Supervisor Mode <0x0-0xFFFFFFFF:8>
|
||
|
;// <o2> Abort Mode <0x0-0xFFFFFFFF:8>
|
||
|
;// <o3> Fast Interrupt Mode <0x0-0xFFFFFFFF:8>
|
||
|
;// <o4> Interrupt Mode <0x0-0xFFFFFFFF:8>
|
||
|
;// <o5> User/System Mode <0x0-0xFFFFFFFF:8>
|
||
|
;// </h>
|
||
|
|
||
|
UND_Stack_Size EQU 512
|
||
|
SVC_Stack_Size EQU 4096
|
||
|
ABT_Stack_Size EQU 512
|
||
|
FIQ_Stack_Size EQU 1024
|
||
|
IRQ_Stack_Size EQU 1024
|
||
|
USR_Stack_Size EQU 512
|
||
|
|
||
|
ISR_Stack_Size EQU (UND_Stack_Size + SVC_Stack_Size + ABT_Stack_Size + \
|
||
|
FIQ_Stack_Size + IRQ_Stack_Size)
|
||
|
|
||
|
AREA STACK, NOINIT, READWRITE, ALIGN=3
|
||
|
|
||
|
Stack_Mem SPACE USR_Stack_Size
|
||
|
__initial_sp SPACE ISR_Stack_Size
|
||
|
Stack_Top
|
||
|
|
||
|
|
||
|
;// <h> Heap Configuration
|
||
|
;// <o> Heap Size (in Bytes) <0x0-0xFFFFFFFF>
|
||
|
;// </h>
|
||
|
|
||
|
Heap_Size EQU 0x00000000
|
||
|
|
||
|
AREA HEAP, NOINIT, READWRITE, ALIGN=3
|
||
|
__heap_base
|
||
|
Heap_Mem SPACE Heap_Size
|
||
|
__heap_limit
|
||
|
|
||
|
|
||
|
;----------------------- Memory Definitions ------------------------------------
|
||
|
|
||
|
AT91_MATRIX_BASE EQU 0xffffee00
|
||
|
AT91_MATRIX_MRCR EQU (AT91_MATRIX_BASE + 0x100)
|
||
|
AT91_MATRIX_RCB0 EQU 0x00000001
|
||
|
AT91_MATRIX_RCB1 EQU 0x00000002
|
||
|
AT91_AIC_BASE EQU 0xfffff000
|
||
|
AT91_AIC_IDCR EQU 0x124
|
||
|
AT91_AIC_ICCR EQU 0x128
|
||
|
|
||
|
;----------------------- CODE --------------------------------------------------
|
||
|
|
||
|
PRESERVE8
|
||
|
|
||
|
|
||
|
; Area Definition and Entry Point
|
||
|
; Startup Code must be linked first at Address at which it expects to run.
|
||
|
|
||
|
AREA RESET, CODE, READONLY
|
||
|
ARM
|
||
|
|
||
|
; Exception Vectors
|
||
|
; Mapped to Address 0.
|
||
|
; Absolute addressing mode must be used.
|
||
|
; Dummy Handlers are implemented as infinite loops which can be modified.
|
||
|
|
||
|
EXPORT Entry_Point
|
||
|
Entry_Point
|
||
|
Vectors LDR PC, Reset_Addr
|
||
|
LDR PC, Undef_Addr
|
||
|
LDR PC, SWI_Addr
|
||
|
LDR PC, PAbt_Addr
|
||
|
LDR PC, DAbt_Addr
|
||
|
NOP
|
||
|
LDR PC, IRQ_Addr
|
||
|
LDR PC, FIQ_Addr
|
||
|
|
||
|
Reset_Addr DCD Reset_Handler
|
||
|
Undef_Addr DCD Undef_Handler
|
||
|
SWI_Addr DCD SWI_Handler
|
||
|
PAbt_Addr DCD PAbt_Handler
|
||
|
DAbt_Addr DCD DAbt_Handler
|
||
|
DCD 0 ; Reserved Address
|
||
|
IRQ_Addr DCD IRQ_Handler
|
||
|
FIQ_Addr DCD FIQ_Handler
|
||
|
|
||
|
Undef_Handler B Undef_Handler
|
||
|
SWI_Handler B SWI_Handler
|
||
|
PAbt_Handler B PAbt_Handler
|
||
|
;DAbt_Handler B DAbt_Handler
|
||
|
FIQ_Handler B FIQ_Handler
|
||
|
|
||
|
;*
|
||
|
;*************************************************************************
|
||
|
;*
|
||
|
;* Interrupt handling
|
||
|
;*
|
||
|
;*************************************************************************
|
||
|
;*
|
||
|
; DAbt Handler
|
||
|
DAbt_Handler
|
||
|
IMPORT rt_hw_trap_dabt
|
||
|
|
||
|
sub sp, sp, #72
|
||
|
stmia sp, {r0 - r12} ;/* Calling r0-r12 */
|
||
|
add r8, sp, #60
|
||
|
stmdb r8, {sp, lr} ;/* Calling SP, LR */
|
||
|
str lr, [r8, #0] ;/* Save calling PC */
|
||
|
mrs r6, spsr
|
||
|
str r6, [r8, #4] ;/* Save CPSR */
|
||
|
str r0, [r8, #8] ;/* Save OLD_R0 */
|
||
|
mov r0, sp
|
||
|
|
||
|
bl rt_hw_trap_dabt
|
||
|
|
||
|
|
||
|
;##########################################
|
||
|
; Reset Handler
|
||
|
|
||
|
EXPORT Reset_Handler
|
||
|
Reset_Handler
|
||
|
|
||
|
|
||
|
; set the cpu to SVC32 mode-----------------------------------------------------
|
||
|
|
||
|
MRS R0,CPSR
|
||
|
BIC R0,R0,#MODEMASK
|
||
|
ORR R0,R0,#SVCMODE
|
||
|
MSR CPSR_cxsf,R0
|
||
|
LDR R1, =AT91_AIC_BASE
|
||
|
LDR R0, =0xffffffff
|
||
|
STR R0, [R1, #AT91_AIC_IDCR]
|
||
|
STR R0, [R1, #AT91_AIC_ICCR]
|
||
|
|
||
|
; remap internal ram to 0x00000000 address
|
||
|
LDR R0, =AT91_MATRIX_MRCR
|
||
|
LDR R1, =(AT91_MATRIX_RCB0|AT91_MATRIX_RCB1)
|
||
|
STR R1, [R0]
|
||
|
|
||
|
|
||
|
; Copy Exception Vectors to Internal RAM ---------------------------------------
|
||
|
|
||
|
ADR R8, Vectors ; Source
|
||
|
LDR R9, =0x00 ; Destination
|
||
|
LDMIA R8!, {R0-R7} ; Load Vectors
|
||
|
STMIA R9!, {R0-R7} ; Store Vectors
|
||
|
LDMIA R8!, {R0-R7} ; Load Handler Addresses
|
||
|
STMIA R9!, {R0-R7} ; Store Handler Addresses
|
||
|
|
||
|
|
||
|
; Setup Stack for each mode ----------------------------------------------------
|
||
|
|
||
|
LDR R0, =Stack_Top
|
||
|
|
||
|
; Enter Undefined Instruction Mode and set its Stack Pointer
|
||
|
MSR CPSR_c, #Mode_UND:OR:I_Bit:OR:F_Bit
|
||
|
MOV SP, R0
|
||
|
SUB R0, R0, #UND_Stack_Size
|
||
|
|
||
|
; Enter Abort Mode and set its Stack Pointer
|
||
|
MSR CPSR_c, #Mode_ABT:OR:I_Bit:OR:F_Bit
|
||
|
MOV SP, R0
|
||
|
SUB R0, R0, #ABT_Stack_Size
|
||
|
|
||
|
; Enter FIQ Mode and set its Stack Pointer
|
||
|
MSR CPSR_c, #Mode_FIQ:OR:I_Bit:OR:F_Bit
|
||
|
MOV SP, R0
|
||
|
SUB R0, R0, #FIQ_Stack_Size
|
||
|
|
||
|
; Enter IRQ Mode and set its Stack Pointer
|
||
|
MSR CPSR_c, #Mode_IRQ:OR:I_Bit:OR:F_Bit
|
||
|
MOV SP, R0
|
||
|
SUB R0, R0, #IRQ_Stack_Size
|
||
|
|
||
|
; Enter Supervisor Mode and set its Stack Pointer
|
||
|
MSR CPSR_c, #Mode_SVC:OR:I_Bit:OR:F_Bit
|
||
|
MOV SP, R0
|
||
|
SUB R0, R0, #SVC_Stack_Size
|
||
|
|
||
|
; Enter User Mode and set its Stack Pointer
|
||
|
; MSR CPSR_c, #Mode_USR
|
||
|
MOV SP, R0
|
||
|
SUB SL, SP, #USR_Stack_Size
|
||
|
|
||
|
; Enter the C code -------------------------------------------------------------
|
||
|
|
||
|
IMPORT __main
|
||
|
LDR R0, =__main
|
||
|
BX R0
|
||
|
|
||
|
IMPORT rt_interrupt_enter
|
||
|
IMPORT rt_interrupt_leave
|
||
|
IMPORT rt_thread_switch_interrput_flag
|
||
|
IMPORT rt_interrupt_from_thread
|
||
|
IMPORT rt_interrupt_to_thread
|
||
|
IMPORT rt_hw_trap_irq
|
||
|
|
||
|
IRQ_Handler PROC
|
||
|
EXPORT IRQ_Handler
|
||
|
STMFD sp!, {r0-r12,lr}
|
||
|
BL rt_interrupt_enter
|
||
|
BL rt_hw_trap_irq
|
||
|
BL rt_interrupt_leave
|
||
|
|
||
|
; if rt_thread_switch_interrput_flag set, jump to
|
||
|
; rt_hw_context_switch_interrupt_do and don't return
|
||
|
LDR r0, =rt_thread_switch_interrput_flag
|
||
|
LDR r1, [r0]
|
||
|
CMP r1, #1
|
||
|
BEQ rt_hw_context_switch_interrupt_do
|
||
|
|
||
|
LDMFD sp!, {r0-r12,lr}
|
||
|
SUBS pc, lr, #4
|
||
|
ENDP
|
||
|
|
||
|
; /*
|
||
|
; * void rt_hw_context_switch_interrupt_do(rt_base_t flag)
|
||
|
; */
|
||
|
rt_hw_context_switch_interrupt_do PROC
|
||
|
EXPORT rt_hw_context_switch_interrupt_do
|
||
|
MOV r1, #0 ; clear flag
|
||
|
STR r1, [r0]
|
||
|
|
||
|
LDMFD sp!, {r0-r12,lr}; reload saved registers
|
||
|
STMFD sp!, {r0-r3} ; save r0-r3
|
||
|
MOV r1, sp
|
||
|
ADD sp, sp, #16 ; restore sp
|
||
|
SUB r2, lr, #4 ; save old task's pc to r2
|
||
|
|
||
|
MRS r3, spsr ; get cpsr of interrupt thread
|
||
|
|
||
|
; switch to SVC mode and no interrupt
|
||
|
MSR cpsr_c, #I_Bit:OR:F_Bit:OR:Mode_SVC
|
||
|
|
||
|
STMFD sp!, {r2} ; push old task's pc
|
||
|
STMFD sp!, {r4-r12,lr}; push old task's lr,r12-r4
|
||
|
MOV r4, r1 ; Special optimised code below
|
||
|
MOV r5, r3
|
||
|
LDMFD r4!, {r0-r3}
|
||
|
STMFD sp!, {r0-r3} ; push old task's r3-r0
|
||
|
STMFD sp!, {r5} ; push old task's cpsr
|
||
|
MRS r4, spsr
|
||
|
STMFD sp!, {r4} ; push old task's spsr
|
||
|
|
||
|
LDR r4, =rt_interrupt_from_thread
|
||
|
LDR r5, [r4]
|
||
|
STR sp, [r5] ; store sp in preempted tasks's TCB
|
||
|
|
||
|
LDR r6, =rt_interrupt_to_thread
|
||
|
LDR r6, [r6]
|
||
|
LDR sp, [r6] ; get new task's stack pointer
|
||
|
|
||
|
LDMFD sp!, {r4} ; pop new task's spsr
|
||
|
MSR spsr_cxsf, r4
|
||
|
LDMFD sp!, {r4} ; pop new task's psr
|
||
|
MSR cpsr_cxsf, r4
|
||
|
|
||
|
LDMFD sp!, {r0-r12,lr,pc} ; pop new task's r0-r12,lr & pc
|
||
|
ENDP
|
||
|
|
||
|
IF :DEF:__MICROLIB
|
||
|
|
||
|
EXPORT __heap_base
|
||
|
EXPORT __heap_limit
|
||
|
|
||
|
ELSE
|
||
|
; User Initial Stack & Heap
|
||
|
AREA |.text|, CODE, READONLY
|
||
|
|
||
|
IMPORT __use_two_region_memory
|
||
|
EXPORT __user_initial_stackheap
|
||
|
__user_initial_stackheap
|
||
|
|
||
|
LDR R0, = Heap_Mem
|
||
|
LDR R1, =(Stack_Mem + USR_Stack_Size)
|
||
|
LDR R2, = (Heap_Mem + Heap_Size)
|
||
|
LDR R3, = Stack_Mem
|
||
|
BX LR
|
||
|
ENDIF
|
||
|
|
||
|
|
||
|
END
|
||
|
|