97 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			97 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
|   | /* | ||
|  |  * Copyright (c) 2006-2018, RT-Thread Development Team | ||
|  |  * | ||
|  |  * SPDX-License-Identifier: Apache-2.0 | ||
|  |  * | ||
|  |  * Change Logs: | ||
|  |  * Date           Author       Notes | ||
|  |  * 2011-01-13     weety    copy from mini2440 | ||
|  |  */ | ||
|  | 
 | ||
|  | /*! | ||
|  |  * \addtogroup ARMv6 | ||
|  |  */ | ||
|  | /*@{*/ | ||
|  | 
 | ||
|  | #include <rtconfig.h> | ||
|  | 
 | ||
|  | #define NOINT          0xc0 | ||
|  | #define FPEXC_EN       (1 << 30) /* VFP enable bit */ | ||
|  | 
 | ||
|  | /* | ||
|  |  * rt_base_t rt_hw_interrupt_disable();
 | ||
|  |  */ | ||
|  | .globl rt_hw_interrupt_disable
 | ||
|  | rt_hw_interrupt_disable: | ||
|  |     mrs r0, cpsr | ||
|  |     cpsid if | ||
|  |     bx  lr | ||
|  | 
 | ||
|  | /* | ||
|  |  * void rt_hw_interrupt_enable(rt_base_t level);
 | ||
|  |  */ | ||
|  | .globl rt_hw_interrupt_enable
 | ||
|  | rt_hw_interrupt_enable: | ||
|  |     msr cpsr_c, r0 | ||
|  |     bx  lr | ||
|  | 
 | ||
|  | /* | ||
|  |  * void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
 | ||
|  |  * r0 --> from | ||
|  |  * r1 --> to | ||
|  |  */ | ||
|  | .globl rt_hw_context_switch
 | ||
|  | rt_hw_context_switch: | ||
|  |     stmfd   sp!, {lr}       @ push pc (lr should be pushed in place of PC)
 | ||
|  |     stmfd   sp!, {r0-r12, lr}   @ push lr & register file
 | ||
|  | 
 | ||
|  |     mrs r4, cpsr | ||
|  |     tst lr, #0x01 | ||
|  |     orrne r4, r4, #0x20     @ it's thumb code
 | ||
|  | 
 | ||
|  |     stmfd sp!, {r4}         @ push cpsr
 | ||
|  | 
 | ||
|  |     str sp, [r0]            @ store sp in preempted tasks TCB
 | ||
|  |     ldr sp, [r1]            @ get new task stack pointer
 | ||
|  | 
 | ||
|  |     ldmfd sp!, {r4}         @ pop new task cpsr to spsr
 | ||
|  |     msr spsr_cxsf, r4 | ||
|  | _do_switch: | ||
|  |     ldmfd sp!, {r0-r12, lr, pc}^  @ pop new task r0-r12, lr & pc, copy spsr to cpsr
 | ||
|  | 
 | ||
|  | /* | ||
|  |  * void rt_hw_context_switch_to(rt_uint32 to);
 | ||
|  |  * r0 --> to | ||
|  |  */ | ||
|  | .globl rt_hw_context_switch_to
 | ||
|  | rt_hw_context_switch_to: | ||
|  |     ldr sp, [r0]            @ get new task stack pointer
 | ||
|  | 
 | ||
|  |     ldmfd sp!, {r4}         @ pop new task spsr
 | ||
|  |     msr spsr_cxsf, r4 | ||
|  | 
 | ||
|  |     bic r4, r4, #0x20       @ must be ARM mode
 | ||
|  |     msr cpsr_cxsf, r4 | ||
|  |     ldmfd sp!, {r0-r12, lr, pc}^   @ pop new task r0-r12, lr & pc
 | ||
|  | 
 | ||
|  | /* | ||
|  |  * void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to);
 | ||
|  |  */ | ||
|  | .globl rt_thread_switch_interrupt_flag
 | ||
|  | .globl rt_interrupt_from_thread
 | ||
|  | .globl rt_interrupt_to_thread
 | ||
|  | .globl rt_hw_context_switch_interrupt
 | ||
|  | rt_hw_context_switch_interrupt: | ||
|  |     ldr r2, =rt_thread_switch_interrupt_flag | ||
|  |     ldr r3, [r2] | ||
|  |     cmp r3, #1 | ||
|  |     beq _reswitch | ||
|  |     mov r3, #1              @ set rt_thread_switch_interrupt_flag to 1
 | ||
|  |     str r3, [r2] | ||
|  |     ldr r2, =rt_interrupt_from_thread   @ set rt_interrupt_from_thread
 | ||
|  |     str r0, [r2] | ||
|  | _reswitch: | ||
|  |     ldr r2, =rt_interrupt_to_thread     @ set rt_interrupt_to_thread
 | ||
|  |     str r1, [r2] | ||
|  |     bx  lr |