From 3ace36ab03f40db05a7876013b7d814a3e5ca171 Mon Sep 17 00:00:00 2001
From: Christian Cunningham <cc@localhost>
Date: Sat, 22 Jan 2022 23:18:22 -0700
Subject: Added SVC call for clean stack
---
src/boot.S | 17 ++++++++++++++---
src/cpu/irq.c | 18 +++++++-----------
src/sys/schedule.S | 2 ++
src/sys/schedule.c | 25 ++++++++++++++-----------
4 files changed, 37 insertions(+), 25 deletions(-)
(limited to 'src')
diff --git a/src/boot.S b/src/boot.S
index 94de57f..aedc957 100644
--- a/src/boot.S
+++ b/src/boot.S
@@ -136,14 +136,25 @@ svc:
// TODO: Make supervisor mode return to a specific location
// (rather than to a user location) such as the kernel loop
cmp r0, #0
- bne 2f
+ bne 3f
cps #0x13
b 1f
-2:
+3:
cmp r0, #2
- bne 1f
+ bne 2f
ldmfd sp!, {r0-r12,lr}
b schedule
+2:
+ cmp r0, #3
+ bne 1f
+ ldr r3, =scheduler
+ ldr r2, [r3, #0]
+ ldr r1, [r2, #8] // sp_base
+ cmp r1, #-1
+ beq 1f
+ ldr r3, =stacks_table
+ mov r0, #0
+ strb r0, [r3, r1]
1:
ldmfd sp!, {r0-r12,pc}^
io_halt_prefetch:
diff --git a/src/cpu/irq.c b/src/cpu/irq.c
index 0ddba2b..729a58d 100644
--- a/src/cpu/irq.c
+++ b/src/cpu/irq.c
@@ -219,11 +219,16 @@ unsigned long c_fiq_handler(void)
}
} else if (source & (1 << 3)) {
c_timer();
- if (counter++ >= 0x10) {
+ counter++;
+ if (counter % 0x60 == 0) {
+ add_thread(localtest, 0, 0);
+ } else if (counter % 0x6000 == 0) {
counter = 0;
+ }
+ if (counter % 0x10 == 0) {
//uart_scheduler();
return 1;
- }
+ }
return 0;
}
return 0;
@@ -231,13 +236,4 @@ unsigned long c_fiq_handler(void)
void localtest(void)
{
- //struct Thread* t = scheduler.rthread_ll->data;
- uart_string("Running IRQ Task...\n");
- //uart_scheduler();
- //uart_10(t->data.pid);
- //uart_char('\n');
- uart_string("Finished!\n");
- //uart_10(t->data.pid);
- //uart_char('\n');
- //sched_info();
}
diff --git a/src/sys/schedule.S b/src/sys/schedule.S
index a4c07c4..8f8ae52 100644
--- a/src/sys/schedule.S
+++ b/src/sys/schedule.S
@@ -58,6 +58,8 @@ cleanup:
ldr r1, [r0, #0]
add r1, #1
str r1, [r0, #0]
+ // cleanup stack
+ svc #3
// usrloop -> rthread
ldr r2, =usrloopthread
str r2, [r3, #0]
diff --git a/src/sys/schedule.c b/src/sys/schedule.c
index 5b311a9..ea5b465 100644
--- a/src/sys/schedule.c
+++ b/src/sys/schedule.c
@@ -4,7 +4,6 @@
#include <util/mutex.h>
extern void kernel_usr_task_loop(void);
-extern void cleanup(void);
void init_scheduler(void)
{
@@ -12,7 +11,7 @@ void init_scheduler(void)
usrloopthread.pc = (void*)kernel_usr_task_loop;
usrloopthread.sp = (void*)0x5FC8;
*(unsigned long**)usrloopthread.sp = (unsigned long*)kernel_usr_task_loop;
- usrloopthread.sp_base = (void*)0x6000;
+ usrloopthread.sp_base = -1;
usrloopthread.mptr = 0;
usrloopthread.pid = -1;
usrloopthread.priority = -1;
@@ -35,25 +34,29 @@ void init_scheduler(void)
nextpid = SCHED_PID + 1;
}
-void* get_stack(void)
+struct RStack get_stack(void)
{
+ struct RStack r = {.sp = 0, .idx = -1};
for (int i = 0; i < MAX_THREADS; i++) {
if (stacks_table[i] == 0) {
stacks_table[i] = 1;
- return (void*)0x20000000 - STACK_SIZE*i;
+ r.idx = i;
+ r.sp = (void*)0x20000000 - STACK_SIZE*i;
+ return r;
}
}
- return 0;
+ return r;
}
void add_thread(void* pc, void* arg, unsigned char priority)
{
- void* sp = get_stack();
+ //void* sp = get_stack();
+ struct RStack r = get_stack();
struct Thread* thread = (struct Thread*)malloca(sizeof(struct Thread), 4);
thread->pc = pc;
- if (sp) {
- thread->sp_base = sp;
- unsigned long* argp = sp;
+ if (r.sp) {
+ thread->sp_base = r.idx;
+ unsigned long* argp = r.sp;
argp -= 1;
*argp = (unsigned long)arg; // Set r0 to the argument
argp -= 13;
@@ -61,8 +64,8 @@ void add_thread(void* pc, void* arg, unsigned char priority)
thread->sp = (void*)argp;
thread->status = THREAD_READY;
} else {
- thread->sp_base = 0;
- thread->sp = 0;
+ thread->sp_base = r.idx;
+ thread->sp = r.sp;
thread->status = THREAD_SERROR;
}
thread->mptr = (void*)0;
--
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