RT-Thread_v4.1.1

libcpu/arm/am335x/context_iar.S

@@ -0,0 +1,82 @@
+;/*
+; * Copyright (c) 2006-2021, RT-Thread Development Team
+; *
+; * SPDX-License-Identifier: Apache-2.0
+; *
+; * Change Logs:
+; * Date           Author       Notes
+; * 2011-08-14     weety      copy from mini2440
+; * 2015-04-15     ArdaFu     convert from context_gcc.s
+; */
+
+#define NOINT            0xc0
+
+    SECTION    .text:CODE(6)
+/*
+ * rt_base_t rt_hw_interrupt_disable();
+ */
+    PUBLIC rt_hw_interrupt_disable
+rt_hw_interrupt_disable:
+    MRS     R0, CPSR
+    ORR     R1, R0, #NOINT
+    MSR     CPSR_C, R1
+    MOV     PC, LR
+
+/*
+ * void rt_hw_interrupt_enable(rt_base_t level);
+ */
+    PUBLIC rt_hw_interrupt_enable
+rt_hw_interrupt_enable:
+    MSR     CPSR_CXSF, R0
+    MOV     PC, LR
+
+/*
+ * void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
+ * r0 --> from
+ * r1 --> to
+ */
+    PUBLIC 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
+    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 spsr
+    MSR     SPSR_cxsf, R4
+    LDMFD   SP!, {R0-R12, LR, PC}^  ; pop new task r0-r12, lr & pc
+
+/*
+ * void rt_hw_context_switch_to(rt_uint32 to);
+ * r0 --> to
+ */
+    PUBLIC 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
+    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);
+ */
+    IMPORT rt_thread_switch_interrupt_flag
+    IMPORT rt_interrupt_from_thread
+    IMPORT rt_interrupt_to_thread
+    PUBLIC 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 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]
+    MOV     PC, LR
+    END
+