321 lines
12 KiB
ArmAsm
321 lines
12 KiB
ArmAsm
|
/*
|
|||
|
|
* Copyright (c) 2006-2022, RT-Thread Development Team
|
|||
|
|
*
|
|||
|
|
* SPDX-License-Identifier: Apache-2.0
|
|||
|
|
*
|
|||
|
|
* Change Logs:
|
|||
|
|
* Date Author Notes
|
|||
|
|
*/
|
|||
|
|
.extern main /* 引入外部C入口 */
|
|||
|
|
|
|||
|
|
.extern rt_interrupt_enter
|
|||
|
|
.extern rt_interrupt_leave
|
|||
|
|
.extern rt_thread_switch_interrupt_flag
|
|||
|
|
.extern rt_interrupt_from_thread
|
|||
|
|
.extern rt_interrupt_to_thread
|
|||
|
|
.extern rt_hw_trap_irq
|
|||
|
|
|
|||
|
|
.global start
|
|||
|
|
.global endless_loop
|
|||
|
|
.global rt_hw_context_switch_interrupt_do
|
|||
|
|
|
|||
|
|
/* Standard definitions of Mode bits and Interrupt (I & F) flags in PSRs */
|
|||
|
|
.set MODE_USR, 0x10 /* User Mode */
|
|||
|
|
.set MODE_FIQ, 0x11 /* FIQ Mode */
|
|||
|
|
.set MODE_IRQ, 0x12 /* IRQ Mode */
|
|||
|
|
.set MODE_SVC, 0x13 /* Supervisor Mode */
|
|||
|
|
.set MODE_ABT, 0x17 /* Abort Mode */
|
|||
|
|
.set MODE_UND, 0x1B /* Undefined Mode */
|
|||
|
|
.set MODE_SYS, 0x1F /* System Mode */
|
|||
|
|
|
|||
|
|
.equ I_BIT, 0x80 /* when I bit is set, IRQ is disabled */
|
|||
|
|
.equ F_BIT, 0x40 /* when F bit is set, FIQ is disabled */
|
|||
|
|
.equ I_Bit, 0x80 /* when I bit is set, IRQ is disabled */
|
|||
|
|
.equ F_Bit, 0x40 /* when F bit is set, FIQ is disabled */
|
|||
|
|
|
|||
|
|
/* VPBDIV definitions*/
|
|||
|
|
.equ VPBDIV, 0xE01FC100
|
|||
|
|
.set VPBDIV_VALUE, 0x00000000
|
|||
|
|
|
|||
|
|
/* Phase Locked Loop (PLL) definitions*/
|
|||
|
|
.equ PLL_BASE, 0xE01FC080 /* PLL Base Address */
|
|||
|
|
.equ PLLCON_OFS, 0x00 /* PLL Control Offset */
|
|||
|
|
.equ PLLCFG_OFS, 0x04 /* PLL Configuration Offset */
|
|||
|
|
.equ PLLSTAT_OFS, 0x08 /* PLL Status Offset */
|
|||
|
|
.equ PLLFEED_OFS, 0x0C /* PLL Feed Offset */
|
|||
|
|
.equ PLLCON_PLLE, (1<<0) /* PLL Enable */
|
|||
|
|
.equ PLLCON_PLLC, (1<<1) /* PLL Connect */
|
|||
|
|
.equ PLLCFG_MSEL, (0x1F<<0) /* PLL Multiplier */
|
|||
|
|
.equ PLLCFG_PSEL, (0x03<<5) /* PLL Divider */
|
|||
|
|
.equ PLLSTAT_PLOCK, (1<<10) /* PLL Lock Status */
|
|||
|
|
.equ PLLCFG_Val, 0x00000024 /* <o1.0..4> MSEL: PLL Multiplier Selection,<o1.5..6> PSEL: PLL Divider Selection */
|
|||
|
|
|
|||
|
|
.equ MEMMAP, 0xE01FC040 /*Memory Mapping Control*/
|
|||
|
|
|
|||
|
|
|
|||
|
|
/* Memory Accelerator Module (MAM) definitions*/
|
|||
|
|
.equ MAM_BASE, 0xE01FC000
|
|||
|
|
.equ MAMCR_OFS, 0x00
|
|||
|
|
.equ MAMTIM_OFS, 0x04
|
|||
|
|
.equ MAMCR_Val, 0x00000002
|
|||
|
|
.equ MAMTIM_Val, 0x00000004
|
|||
|
|
|
|||
|
|
.equ VICIntEnClr, 0xFFFFF014
|
|||
|
|
.equ VICIntSelect, 0xFFFFF00C
|
|||
|
|
/************* 目标配置结束 *************/
|
|||
|
|
|
|||
|
|
|
|||
|
|
/* Setup the operating mode & stack.*/
|
|||
|
|
/* --------------------------------- */
|
|||
|
|
.global _reset
|
|||
|
|
_reset:
|
|||
|
|
.code 32
|
|||
|
|
.align 0
|
|||
|
|
|
|||
|
|
/************************* PLL_SETUP **********************************/
|
|||
|
|
ldr r0, =PLL_BASE
|
|||
|
|
mov r1, #0xAA
|
|||
|
|
mov r2, #0x55
|
|||
|
|
|
|||
|
|
/* Configure and Enable PLL */
|
|||
|
|
mov r3, #PLLCFG_Val
|
|||
|
|
str r3, [r0, #PLLCFG_OFS]
|
|||
|
|
mov r3, #PLLCON_PLLE
|
|||
|
|
str r3, [r0, #PLLCON_OFS]
|
|||
|
|
str r1, [r0, #PLLFEED_OFS]
|
|||
|
|
str r2, [r0, #PLLFEED_OFS]
|
|||
|
|
|
|||
|
|
/* Wait until PLL Locked */
|
|||
|
|
PLL_Locked_loop:
|
|||
|
|
ldr r3, [r0, #PLLSTAT_OFS]
|
|||
|
|
ands r3, r3, #PLLSTAT_PLOCK
|
|||
|
|
beq PLL_Locked_loop
|
|||
|
|
|
|||
|
|
/* Switch to PLL Clock */
|
|||
|
|
mov r3, #(PLLCON_PLLE|PLLCON_PLLC)
|
|||
|
|
str r3, [r0, #PLLCON_OFS]
|
|||
|
|
str r1, [r0, #PLLFEED_OFS]
|
|||
|
|
str R2, [r0, #PLLFEED_OFS]
|
|||
|
|
/************************* PLL_SETUP **********************************/
|
|||
|
|
|
|||
|
|
/************************ Setup VPBDIV ********************************/
|
|||
|
|
ldr r0, =VPBDIV
|
|||
|
|
ldr r1, =VPBDIV_VALUE
|
|||
|
|
str r1, [r0]
|
|||
|
|
/************************ Setup VPBDIV ********************************/
|
|||
|
|
|
|||
|
|
/************** Setup MAM **************/
|
|||
|
|
ldr r0, =MAM_BASE
|
|||
|
|
mov r1, #MAMTIM_Val
|
|||
|
|
str r1, [r0, #MAMTIM_OFS]
|
|||
|
|
mov r1, #MAMCR_Val
|
|||
|
|
str r1, [r0, #MAMCR_OFS]
|
|||
|
|
/************** Setup MAM **************/
|
|||
|
|
|
|||
|
|
/************************ setup stack *********************************/
|
|||
|
|
ldr r0, .undefined_stack_top
|
|||
|
|
sub r0, r0, #4
|
|||
|
|
msr CPSR_c, #MODE_UND|I_BIT|F_BIT /* Undefined Instruction Mode */
|
|||
|
|
mov sp, r0
|
|||
|
|
|
|||
|
|
ldr r0, .abort_stack_top
|
|||
|
|
sub r0, r0, #4
|
|||
|
|
msr CPSR_c, #MODE_ABT|I_BIT|F_BIT /* Abort Mode */
|
|||
|
|
mov sp, r0
|
|||
|
|
|
|||
|
|
ldr r0, .fiq_stack_top
|
|||
|
|
sub r0, r0, #4
|
|||
|
|
msr CPSR_c, #MODE_FIQ|I_BIT|F_BIT /* FIQ Mode */
|
|||
|
|
mov sp, r0
|
|||
|
|
|
|||
|
|
ldr r0, .irq_stack_top
|
|||
|
|
sub r0, r0, #4
|
|||
|
|
msr CPSR_c, #MODE_IRQ|I_BIT|F_BIT /* IRQ Mode */
|
|||
|
|
mov sp, r0
|
|||
|
|
|
|||
|
|
ldr r0, .svc_stack_top
|
|||
|
|
sub r0, r0, #4
|
|||
|
|
msr CPSR_c, #MODE_SVC|I_BIT|F_BIT /* Supervisor Mode */
|
|||
|
|
mov sp, r0
|
|||
|
|
/************************ setup stack ********************************/
|
|||
|
|
|
|||
|
|
/* copy .data to SRAM */
|
|||
|
|
ldr r1, =_sidata /* .data start in image */
|
|||
|
|
ldr r2, =_edata /* .data end in image */
|
|||
|
|
ldr r3, =_sdata /* sram data start */
|
|||
|
|
data_loop:
|
|||
|
|
ldr r0, [r1, #0]
|
|||
|
|
str r0, [r3]
|
|||
|
|
|
|||
|
|
add r1, r1, #4
|
|||
|
|
add r3, r3, #4
|
|||
|
|
|
|||
|
|
cmp r3, r2 /* check if data to clear */
|
|||
|
|
blo data_loop /* loop until done */
|
|||
|
|
|
|||
|
|
/* clear .bss */
|
|||
|
|
mov r0,#0 /* get a zero */
|
|||
|
|
ldr r1,=__bss_start /* bss start */
|
|||
|
|
ldr r2,=__bss_end /* bss end */
|
|||
|
|
|
|||
|
|
bss_loop:
|
|||
|
|
cmp r1,r2 /* check if data to clear */
|
|||
|
|
strlo r0,[r1],#4 /* clear 4 bytes */
|
|||
|
|
blo bss_loop /* loop until done */
|
|||
|
|
|
|||
|
|
|
|||
|
|
/* call C++ constructors of global objects */
|
|||
|
|
ldr r0, =__ctors_start__
|
|||
|
|
ldr r1, =__ctors_end__
|
|||
|
|
|
|||
|
|
ctor_loop:
|
|||
|
|
cmp r0, r1
|
|||
|
|
beq ctor_end
|
|||
|
|
ldr r2, [r0], #4
|
|||
|
|
stmfd sp!, {r0-r1}
|
|||
|
|
mov lr, pc
|
|||
|
|
bx r2
|
|||
|
|
ldmfd sp!, {r0-r1}
|
|||
|
|
b ctor_loop
|
|||
|
|
ctor_end:
|
|||
|
|
|
|||
|
|
/* enter C code */
|
|||
|
|
bl main
|
|||
|
|
|
|||
|
|
.align 0
|
|||
|
|
.undefined_stack_top:
|
|||
|
|
.word _undefined_stack_top
|
|||
|
|
.abort_stack_top:
|
|||
|
|
.word _abort_stack_top
|
|||
|
|
.fiq_stack_top:
|
|||
|
|
.word _fiq_stack_top
|
|||
|
|
.irq_stack_top:
|
|||
|
|
.word _irq_stack_top
|
|||
|
|
.svc_stack_top:
|
|||
|
|
.word _svc_stack_top
|
|||
|
|
/*********************** END Clear BSS ******************************/
|
|||
|
|
|
|||
|
|
.section .init,"ax"
|
|||
|
|
.code 32
|
|||
|
|
.align 0
|
|||
|
|
.globl _start
|
|||
|
|
_start:
|
|||
|
|
|
|||
|
|
ldr pc, __start /* reset - _start */
|
|||
|
|
ldr pc, _undf /* undefined - _undf */
|
|||
|
|
ldr pc, _swi /* SWI - _swi */
|
|||
|
|
ldr pc, _pabt /* program abort - _pabt */
|
|||
|
|
ldr pc, _dabt /* data abort - _dabt */
|
|||
|
|
.word 0xB8A06F58 /* reserved */
|
|||
|
|
ldr pc, __IRQ_Handler /* IRQ - read the VIC */
|
|||
|
|
ldr pc, _fiq /* FIQ - _fiq */
|
|||
|
|
|
|||
|
|
__start:.word _reset
|
|||
|
|
_undf: .word __undf /* undefined */
|
|||
|
|
_swi: .word __swi /* SWI */
|
|||
|
|
_pabt: .word __pabt /* program abort */
|
|||
|
|
_dabt: .word __dabt /* data abort */
|
|||
|
|
temp1: .word 0
|
|||
|
|
__IRQ_Handler: .word IRQ_Handler
|
|||
|
|
_fiq: .word __fiq /* FIQ */
|
|||
|
|
|
|||
|
|
__undf: b . /* undefined */
|
|||
|
|
__swi : b .
|
|||
|
|
__pabt: b . /* program abort */
|
|||
|
|
__dabt: b . /* data abort */
|
|||
|
|
__fiq : b . /* FIQ */
|
|||
|
|
|
|||
|
|
/* IRQ入口 */
|
|||
|
|
IRQ_Handler :
|
|||
|
|
stmfd sp!, {r0-r12,lr} /* 对R0 – R12，LR寄存器压栈 */
|
|||
|
|
bl rt_interrupt_enter /* 通知RT-Thread进入中断模式 */
|
|||
|
|
bl rt_hw_trap_irq /* 相应中断服务例程处理 */
|
|||
|
|
bl rt_interrupt_leave /* ; 通知RT-Thread要离开中断模式 */
|
|||
|
|
|
|||
|
|
/* 如果设置了rt_thread_switch_interrupt_flag，进行中断中的线程上下文处理 */
|
|||
|
|
ldr r0, =rt_thread_switch_interrupt_flag
|
|||
|
|
ldr r1, [r0]
|
|||
|
|
cmp r1, #1
|
|||
|
|
beq rt_hw_context_switch_interrupt_do /* 中断中切换发生 */
|
|||
|
|
/* 如果跳转了，将不会回来 */
|
|||
|
|
ldmfd sp!, {r0-r12,lr} /* 恢复栈 */
|
|||
|
|
subs pc, lr, #4 /* 从IRQ中返回 */
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* void rt_hw_context_switch_interrupt_do(rt_base_t flag)
|
|||
|
|
* 中断结束后的上下文切换
|
|||
|
|
*/
|
|||
|
|
rt_hw_context_switch_interrupt_do:
|
|||
|
|
mov r1, #0 /* clear flag */
|
|||
|
|
/* 清楚中断中切换标志 */
|
|||
|
|
str r1, [r0] /* */
|
|||
|
|
|
|||
|
|
ldmfd sp!, {r0-r12,lr}/* reload saved registers */
|
|||
|
|
/* 先恢复被中断线程的上下文 */
|
|||
|
|
stmfd sp!, {r0-r3} /* save r0-r3 */
|
|||
|
|
/* 对R0 – R3压栈，因为后面会用到 */
|
|||
|
|
mov r1, sp /* 把此处的栈值保存到R1 */
|
|||
|
|
add sp, sp, #16 /* restore sp */
|
|||
|
|
/* 恢复IRQ的栈，后面会跳出IRQ模式 */
|
|||
|
|
sub r2, lr, #4 /* save old task's pc to r2 */
|
|||
|
|
/* 保存切换出线程的PC到R2 */
|
|||
|
|
|
|||
|
|
mrs r3, spsr /* disable interrupt 保存中断前的CPSR到R3寄存器 */
|
|||
|
|
/* 获得SPSR寄存器值 */
|
|||
|
|
orr r0, r3, #I_BIT|F_BIT
|
|||
|
|
msr spsr_c, r0 /* 关闭SPSR中的IRQ/FIQ中断 */
|
|||
|
|
|
|||
|
|
ldr r0, =.+8 /* 把当前地址+8载入到R0寄存器中 switch to interrupted task's stack */
|
|||
|
|
movs pc, r0 /* 退出IRQ模式，由于SPSR被设置成关中断模式 */
|
|||
|
|
/* 所以从IRQ返回后，中断并没有打开
|
|||
|
|
; R0寄存器中的位置实际就是下一条指令，
|
|||
|
|
; 即PC继续往下走
|
|||
|
|
; 此时
|
|||
|
|
; 模式已经换成中断前的SVC模式，
|
|||
|
|
; SP寄存器也是SVC模式下的栈寄存器
|
|||
|
|
; R1保存IRQ模式下的栈指针
|
|||
|
|
; R2保存切换出线程的PC
|
|||
|
|
; R3保存切换出线程的CPSR */
|
|||
|
|
stmfd sp!, {r2} /* push old task's pc */
|
|||
|
|
/* 保存切换出任务的PC */
|
|||
|
|
stmfd sp!, {r4-r12,lr}/* push old task's lr,r12-r4 */
|
|||
|
|
/* 保存R4 – R12，LR寄存器 */
|
|||
|
|
mov r4, r1 /* Special optimised code below */
|
|||
|
|
/* R1保存有压栈R0 – R3处的栈位置 */
|
|||
|
|
mov r5, r3 /* R3切换出线程的CPSR */
|
|||
|
|
ldmfd r4!, {r0-r3} /* 恢复R0 – R3 */
|
|||
|
|
stmfd sp!, {r0-r3} /* push old task's r3-r0 */
|
|||
|
|
/* R0 – R3压栈到切换出线程 */
|
|||
|
|
stmfd sp!, {r5} /* push old task's psr */
|
|||
|
|
/* 切换出线程CPSR压栈 */
|
|||
|
|
mrs r4, spsr
|
|||
|
|
stmfd sp!, {r4} /* push old task's spsr */
|
|||
|
|
/* 切换出线程SPSR压栈 */
|
|||
|
|
|
|||
|
|
ldr r4, =rt_interrupt_from_thread
|
|||
|
|
ldr r5, [r4]
|
|||
|
|
str sp, [r5] /* store sp in preempted tasks's TCB */
|
|||
|
|
/* 保存切换出线程的SP指针 */
|
|||
|
|
|
|||
|
|
ldr r6, =rt_interrupt_to_thread
|
|||
|
|
ldr r6, [r6]
|
|||
|
|
ldr sp, [r6] /* get new task's stack pointer */
|
|||
|
|
/* 获得切换到线程的栈 */
|
|||
|
|
|
|||
|
|
ldmfd sp!, {r4} /* pop new task's spsr */
|
|||
|
|
/* 恢复SPSR */
|
|||
|
|
msr SPSR_cxsf, r4
|
|||
|
|
ldmfd sp!, {r4} /* pop new task's psr */
|
|||
|
|
/* 恢复CPSR */
|
|||
|
|
msr CPSR_cxsf, r4
|
|||
|
|
|
|||
|
|
ldmfd sp!, {r0-r12,lr,pc} /* pop new task's r0-r12,lr & pc */
|
|||
|
|
/* 恢复R0 – R12，LR及PC寄存器 */
|
|||
|
|
|
|||
|
|
/* 代码加密功能 */
|
|||
|
|
#if defined(CODE_PROTECTION)
|
|||
|
|
.org 0x01FC
|
|||
|
|
.word 0x87654321
|
|||
|
|
#endif
|
|||
|
|
|