xref: /nrf52832-nimble/rt-thread/libcpu/arm/armv6/context_gcc.S (revision 104654410c56c573564690304ae786df310c91fc)
1/*
2 * Copyright (c) 2006-2018, RT-Thread Development Team
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 *
6 * Change Logs:
7 * Date           Author       Notes
8 * 2011-01-13     weety    copy from mini2440
9 */
10
11/*!
12 * \addtogroup ARMv6
13 */
14/*@{*/
15
16#include <rtconfig.h>
17
18#define NOINT          0xc0
19#define FPEXC_EN       (1 << 30) /* VFP enable bit */
20
21/*
22 * rt_base_t rt_hw_interrupt_disable();
23 */
24.globl rt_hw_interrupt_disable
25rt_hw_interrupt_disable:
26    mrs r0, cpsr
27    cpsid if
28    bx  lr
29
30/*
31 * void rt_hw_interrupt_enable(rt_base_t level);
32 */
33.globl rt_hw_interrupt_enable
34rt_hw_interrupt_enable:
35    msr cpsr_c, r0
36    bx  lr
37
38/*
39 * void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
40 * r0 --> from
41 * r1 --> to
42 */
43.globl rt_hw_context_switch
44rt_hw_context_switch:
45    stmfd   sp!, {lr}       @ push pc (lr should be pushed in place of PC)
46    stmfd   sp!, {r0-r12, lr}   @ push lr & register file
47
48    mrs r4, cpsr
49    tst lr, #0x01
50    orrne r4, r4, #0x20     @ it's thumb code
51
52    stmfd sp!, {r4}         @ push cpsr
53
54    str sp, [r0]            @ store sp in preempted tasks TCB
55    ldr sp, [r1]            @ get new task stack pointer
56
57    ldmfd sp!, {r4}         @ pop new task cpsr to spsr
58    msr spsr_cxsf, r4
59_do_switch:
60    ldmfd sp!, {r0-r12, lr, pc}^  @ pop new task r0-r12, lr & pc, copy spsr to cpsr
61
62/*
63 * void rt_hw_context_switch_to(rt_uint32 to);
64 * r0 --> to
65 */
66.globl rt_hw_context_switch_to
67rt_hw_context_switch_to:
68    ldr sp, [r0]            @ get new task stack pointer
69
70    ldmfd sp!, {r4}         @ pop new task spsr
71    msr spsr_cxsf, r4
72
73    bic r4, r4, #0x20       @ must be ARM mode
74    msr cpsr_cxsf, r4
75    ldmfd sp!, {r0-r12, lr, pc}^   @ pop new task r0-r12, lr & pc
76
77/*
78 * void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to);
79 */
80.globl rt_thread_switch_interrupt_flag
81.globl rt_interrupt_from_thread
82.globl rt_interrupt_to_thread
83.globl rt_hw_context_switch_interrupt
84rt_hw_context_switch_interrupt:
85    ldr r2, =rt_thread_switch_interrupt_flag
86    ldr r3, [r2]
87    cmp r3, #1
88    beq _reswitch
89    mov r3, #1              @ set rt_thread_switch_interrupt_flag to 1
90    str r3, [r2]
91    ldr r2, =rt_interrupt_from_thread   @ set rt_interrupt_from_thread
92    str r0, [r2]
93_reswitch:
94    ldr r2, =rt_interrupt_to_thread     @ set rt_interrupt_to_thread
95    str r1, [r2]
96    bx  lr
97