commit 1a94ee7b7fcc0b4c9a81ea605cf451879ab7836f
parent 6ca5a365f12207ef72e483c3fb1870763bb8f153
Author: Matsuda Kenji <info@mtkn.jp>
Date: Sun, 17 Mar 2024 10:22:00 +0900
dump context
Diffstat:
| M | ex3/main.c | | | 60 | ++++++++++++++++++++---------------------------------------- |
| M | ex3/proc.s | | | 107 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------- |
2 files changed, 96 insertions(+), 71 deletions(-)
diff --git a/ex3/main.c b/ex3/main.c
@@ -2,26 +2,26 @@
void init(void);
int puts(char *);
-void printh(void *);
+void printh(unsigned int);
void set_alarm(unsigned int);
void proc0(void);
void halt(void);
-void *get_sp(void);
void wfi(void);
+void print_sp(void);
void *memcpy(void *s1, void *s2, long n);
-void setreg(void);
// A proc represents a process in execution.
typedef struct proc {
// Id is the unique identifier of the process.
unsigned int id;
- // R is the registers of the process with r[13] be sp, r[14] lr, r[15] pc.
- void *r[16];
+ // R is the registers of the process with
+ // r[13] be sp, r[14] lr, r[15] pc, r16 xspr.
+ unsigned int r[17];
// Next is the next process to execute.
struct proc *next;
} proc;
-proc *save_context(unsigned int pid, void *r[16]);
+void save_context(unsigned int r[17]);
extern char proc0_start, proc0_size;
extern char proc1_start, proc1_size;
@@ -51,56 +51,36 @@ main(void) {
ptab.tail = &p1;
p0.id = 0;
- p0.r[13] = (void *) 0x20000100; // sp
- p0.r[14] = (void *) main; // lr
- p0.r[15] = (void *) 0x20000000; // pc
+ p0.r[13] = 0x20000100; // sp
+ p0.r[14] = (unsigned int) main; // lr
+ p0.r[15] = 0x20000000; // pc
p0.next = &p1;
p1.id = 1;
- p1.r[13] = (void *) 0x20000200; // sp
- p1.r[14] = (void *) main; // lr
- p1.r[15] = (void *) 0x20000100; // pc
+ p1.r[13] = 0x20000200; // sp
+ p1.r[14] = (unsigned int) main; // lr
+ p1.r[15] = 0x20000100; // pc
p1.next = NULL;
for (;;) {
- setreg();
wfi();
- void *r[16] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
- proc *p = save_context(0, r);
- if (p == NULL) {
- puts("process 0 not found");
- continue;
- }
- for (int i = 0; i < 16; i++) {
- printh(p0.r[i]);
+ for (int i = 0; i < 17; i++) {
+ printh(ptab.head->r[i]);
puts("");
}
- puts("");
}
return 0;
}
-// Save_context saves registers r to the proc struct specified by pid.
-// It returns the address of matching process, or NULL if no such process is found.
-proc *
-save_context(unsigned int pid, void *r[16])
+// Save_context saves the context starting at sp to the current proc struct.
+void
+save_context(unsigned int r[17])
{
- proc *p;
+ puts("save_context");
int i;
-
- for (p = ptab.head; p; p = p->next) {
- if (p->id == pid) {
- break;
- }
- }
- if (!p) {
- return NULL;
- }
-
- for (i = 0; i < 16; i++) {
- p->r[i] = r[i];
+ for (i = 0; i < 17; i++) {
+ ptab.head->r[i] = r[i];
}
- return p;
}
void
diff --git a/ex3/proc.s b/ex3/proc.s
@@ -20,41 +20,86 @@ proc1:
msg1:
.asciz "proc1"
- .section .text
- // void *get_sp(void);
- // Get_sp returns the current stack pointer.
- .global get_sp
-get_sp:
+ .global print_sp
+print_sp:
+ mov r4, lr
mov r0, sp
- bx lr
-
- // Setreg sets registers for debugging.
- // Modified registers are:
- // LR, R12, R3, R2, R1 and R0.
- .global setreg
-setreg:
- push {lr}
- mov r0, #0x12
- mov r12, r0
- mov r0, #0x14
- mov lr, r0
- mov r0, #0
- mov r1, #1
- mov r2, #2
- mov r3, #3
- nop
- pop {pc}
-
- .global print_sr
-print_sr:
- push {lr}
- mrs r0, ipsr
bl printh
- pop {pc}
+ bx r4
.global isr_alarm
isr_alarm:
- push {r4, r5, r6, lr}
+ push {lr}
+ sub sp, sp, #(17*4) // unsigned int r[17];
+ mov r1, sp
+
+ mov r2, #(17*4 + 4) // +4 for pushed lr
+ mov r3, #0
+ ldr r0, [r1, r2] // r0
+ str r0, [r1, r3]
+ add r2, r2, #4
+ add r3, r3, #4
+ ldr r0, [r1, r2] // r1
+ str r0, [r1, r3]
+ add r2, r2, #4
+ add r3, r3, #4
+ ldr r0, [r1, r2] // r2
+ str r0, [r1, r3]
+ add r2, r2, #4
+ add r3, r3, #4
+ ldr r0, [r1, r2] // r3
+ str r0, [r1, r3]
+
+ add r3, r3, #4
+ str r4, [r1, r3] // r4
+ add r3, r3, #4
+ str r5, [r1, r3] // r5
+ add r3, r3, #4
+ str r6, [r1, r3] // r6
+ add r3, r3, #4
+ str r7, [r1, r3] // r7
+
+ add r3, r3, #4
+ mov r0, r8
+ str r0, [r1, r3] // r8
+ add r3, r3, #4
+ mov r0, r9
+ str r0, [r1, r3] // r9
+ add r3, r3, #4
+ mov r0, r10
+ str r0, [r1, r3] // r10
+ add r3, r3, #4
+ mov r0, r11
+ str r0, [r1, r3] // r11
+
+ add r2, r2, #4
+ add r3, r3, #4
+ ldr r0, [r1, r2]
+ str r0, [r1, r3] // r12
+
+ add r3, r3, #4
+ mov r0, sp
+ str r0, [r1, r3] // sp ???
+
+ add r2, r2, #4
+ add r3, r3, #4
+ ldr r0, [r1, r2]
+ str r0, [r1, r3] // lr
+
+ add r2, r2, #4
+ add r3, r3, #4
+ ldr r0, [r1, r2]
+ str r0, [r1, r3] // ReturnAddress(ExceptionType): The next pc at interrupt.
+
+ add r2, r2, #4
+ add r3, r3, #4
+ ldr r0, [r1, r2] // xpsr
+ str r0, [r1, r3]
+
+ mov r0, r1
+ bl save_context
+
+ add sp, sp, #(17*4)
ldr r0, =(1000 * 1000)
bl set_alarm
- pop {r4, r5, r6, pc}
+ pop {pc}
