rp2040

commit e7760c1a36c1865d4df268b65cd8d53a126a7d3d
parent 2ba7851cb24ada3e4ab910f8822dcb7095b74252
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Fri, 22 Mar 2024 08:32:34 +0900

switch context

Diffstat:
M
ex3/main.c
 | 
17
++++++++++++-----
M
ex3/proc.s
 | 
7
+++----

2 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/ex3/main.c b/ex3/main.c
@@ -4,7 +4,6 @@ void init(void);
 int puts(char *);
 void printh(unsigned int);
 void set_alarm(unsigned int);
-void proc0(void);
 void halt(void);
 void wfi(void);
 void print_sp(void);
@@ -26,8 +25,8 @@ void save_context(unsigned int r[17]);
 
 extern char proc0_start, proc0_size;
 extern char proc1_start, proc1_size;
-extern char msg0;
-extern char msg1;
+extern void proc0(void), proc1(void);
+extern char msg0, msg1;
 
 
 // A proc_tab is the queue of waiting processes.
@@ -54,17 +53,19 @@ main(void) {
 	p0.id = 0;
 	p0.r[13] = 0x20000100; // sp
 	p0.r[14] = (unsigned int) halt; // lr
-	p0.r[15] = 0x20000001; // pc
+	p0.r[15] = (unsigned int) proc0 + 1; // pc
 	p0.r[16] = 0;
 	p0.next = &p1;
 
 	p1.id = 1;
 	p1.r[13] = 0x20000200; // sp
 	p1.r[14] = (unsigned int) halt; // lr
-	p1.r[15] = 0x20000101; // pc
+	p1.r[15] = (unsigned int) proc1 + 1; // pc
 	p1.r[16] = 0;
 	p1.next = NULL;
 
+	proc0();
+
 	return 0;
 }
 
@@ -80,6 +81,12 @@ unsigned int *
 switch_context(unsigned int r[17]) {
 	proc *p;
 
+	puts("switch_context:");
+	for (int i = 0; i < 17; i++) {
+		printh(r[i]);
+		puts("");
+	}
+
 	// save context
 	int i;
 	for (i = 0; i < 17; i++) {
diff --git a/ex3/proc.s b/ex3/proc.s
@@ -111,7 +111,6 @@ isr_alarm:
 	bl switch_context // r0 is the r[17] of the next task.
 	add sp, sp, #(17*4)
 	add r2, sp, #4 // for the popped lr
-/*
 	ldr r1, [r0, #(0 * 4)] // r0
 	str r1, [r2, #0]
 	ldr r1, [r0, #(1 * 4)] // r1
@@ -126,9 +125,9 @@ isr_alarm:
 	str r1, [r2, #0x14]
 	ldr r1, [r0, #(15 * 4)] // ReturnAddress
 	str r1, [r2, #0x18]
-	ldr r1, [r0, #(16 * 4)] // xpsr
-	str r1, [r2, #0x1c]
-*/
+//	ldr r1, [r0, #(16 * 4)] // xpsr
+//	str r1, [r2, #0x1c]
+
 	mov r4, r0
 
 	ldr r0, =(1000 * 1000)