From e15d41a5619c41f3440369e625d6d96921718221 Mon Sep 17 00:00:00 2001
From: Christian Cunningham <cc@localhost>
Date: Thu, 30 Dec 2021 20:50:44 -0800
Subject: Added Data Structures
Added basic scheduling
TODO: Preserve registers for context switch
---
src/lib/ll.c | 32 +++++++++++++++++++++
src/lib/ll.h | 24 ++++++++++++++++
src/lib/mem.c | 19 +++++++++++++
src/lib/mem.h | 3 ++
src/lib/q.c | 38 +++++++++++++++++++++++++
src/lib/q.h | 30 ++++++++++++++++++++
src/sys/core.c | 3 ++
src/sys/schedule.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/sys/schedule.h | 29 +++++++++++++++++++
9 files changed, 259 insertions(+)
create mode 100644 src/lib/ll.c
create mode 100644 src/lib/ll.h
create mode 100644 src/lib/q.c
create mode 100644 src/lib/q.h
create mode 100644 src/sys/schedule.c
create mode 100644 src/sys/schedule.h
(limited to 'src')
diff --git a/src/lib/ll.c b/src/lib/ll.c
new file mode 100644
index 0000000..6d96f45
--- /dev/null
+++ b/src/lib/ll.c
@@ -0,0 +1,32 @@
+#include "../lib/ll.h"
+#include "../lib/mem.h"
+
+struct LL* new(void* val)
+{
+ struct LL* ll = (struct LL*)malloc(sizeof(struct LL));
+ ll->prev = ll;
+ ll->next = ll;
+ ll->data = val;
+ return ll;
+}
+
+void push(struct LL* l, void* val)
+{
+ struct LL* ll = (struct LL*)malloc(sizeof(struct LL));
+ ll->prev = l->prev;
+ ll->next = l;
+ ll->prev->next = ll;
+ l->prev = ll;
+ ll->data = val;
+}
+
+void remove(struct LL* l, unsigned long idx)
+{
+ struct LL* t = l;
+ for(unsigned long i = 0; i < idx; i++) {
+ t = t->next;
+ }
+ t->prev->next = t->next;
+ t->next->prev = t->prev;
+ free(t);
+}
diff --git a/src/lib/ll.h b/src/lib/ll.h
new file mode 100644
index 0000000..4a11620
--- /dev/null
+++ b/src/lib/ll.h
@@ -0,0 +1,24 @@
+#ifndef LIB_LL_H
+#define LIB_LL_H
+
+struct LL {
+ struct LL* prev;
+ struct LL* next;
+ void* data;
+};
+
+struct LL* new(void* val);
+void push(struct LL* l, void* val);
+void remove(struct LL* l, unsigned long idx);
+
+#define showl(L, TYPE) { \
+ struct LL* t = L; \
+ do { \
+ uart_hex(*(TYPE*)t->data); \
+ t = t->next; \
+ if (t != l) \
+ uart_char(' '); \
+ } while (t != l); \
+}
+
+#endif
diff --git a/src/lib/mem.c b/src/lib/mem.c
index 3683ae7..0069623 100644
--- a/src/lib/mem.c
+++ b/src/lib/mem.c
@@ -41,3 +41,22 @@ unsigned char memcmp32(unsigned long* a, unsigned long* b, unsigned int n)
}
return 1;
}
+
+#define MAX_MM 0x100000
+static unsigned char rpi_heap[MAX_MM] = {0,};
+
+void* malloc(unsigned char size)
+{
+ unsigned char* mem = (unsigned char*)rpi_heap;
+ unsigned long i = 0;
+ while (mem[i] != 0) {
+ i += mem[i]+1;
+ }
+ mem[i] = size;
+ return (void*)&mem[i+1];
+}
+
+void free(__attribute__((unused)) void* memloc)
+{
+ // TODO: Implement free
+}
diff --git a/src/lib/mem.h b/src/lib/mem.h
index 67e2717..4fdae78 100644
--- a/src/lib/mem.h
+++ b/src/lib/mem.h
@@ -8,4 +8,7 @@ void memshow32(unsigned long* addr, unsigned int n);
void memcpy32(unsigned long* src, unsigned long* dest, unsigned int n);
unsigned char memcmp32(unsigned long* a, unsigned long* b, unsigned int n);
+void* malloc(unsigned char size);
+void free(void* memloc);
+
#endif
diff --git a/src/lib/q.c b/src/lib/q.c
new file mode 100644
index 0000000..e40fee8
--- /dev/null
+++ b/src/lib/q.c
@@ -0,0 +1,38 @@
+#include "../lib/q.h"
+#include "../lib/mem.h"
+
+struct Q_base* newq()
+{
+ struct Q_base* q = (struct Q_base*)malloc(sizeof(struct Q_base));
+ q->next = 0;
+ q->last = 0;
+ return q;
+}
+
+void pushq(struct Q_base* qb, void* val)
+{
+ struct Q* n = (struct Q*)malloc(sizeof(struct Q));
+ n->next = 0;
+ n->data = val;
+ if (qb->last != 0)
+ qb->last->next = n;
+ else {
+ qb->next = n;
+ }
+ qb->last = n;
+}
+
+void popq(struct Q_base* qb)
+{
+ if (qb->next == 0)
+ return;
+ if (qb->next == qb->last) {
+ free(qb->next);
+ qb->next = 0;
+ qb->last = 0;
+ return;
+ }
+ struct Q* t = qb->next;
+ qb->next = qb->next->next;
+ free(t);
+}
diff --git a/src/lib/q.h b/src/lib/q.h
new file mode 100644
index 0000000..51ff1a1
--- /dev/null
+++ b/src/lib/q.h
@@ -0,0 +1,30 @@
+#ifndef LIB_Q_H
+#define LIB_Q_H
+
+struct Q_base {
+ struct Q* next;
+ struct Q* last;
+};
+
+struct Q {
+ struct Q* next;
+ void* data;
+};
+
+struct Q_base* newq();
+void pushq(struct Q_base* qb, void* val);
+void popq(struct Q_base* qb);
+
+#define showq(QQ, TYPE) { \
+ if (QQ->next != 0) { \
+ struct Q* t = QQ->next; \
+ while (t->next != 0) { \
+ uart_hex(*(TYPE*)t->data); \
+ t = t->next; \
+ uart_char(' '); \
+ } \
+ uart_hex(*(TYPE*)t->data); \
+ } \
+}
+
+#endif
diff --git a/src/sys/core.c b/src/sys/core.c
index f75ec35..ebf50a0 100644
--- a/src/sys/core.c
+++ b/src/sys/core.c
@@ -2,10 +2,13 @@
#include "../drivers/uart.h"
#include "../graphics/drawer.h"
#include "../graphics/lfb.h"
+#include "../lib/ll.h"
#include "../lib/mem.h"
+#include "../lib/q.h"
#include "../lib/strings.h"
#include "../sys/core.h"
#include "../sys/power.h"
+#include "../sys/schedule.h"
#include "../sys/timer.h"
#include "../util/mutex.h"
#include "../util/time.h"
diff --git a/src/sys/schedule.c b/src/sys/schedule.c
new file mode 100644
index 0000000..f920b0e
--- /dev/null
+++ b/src/sys/schedule.c
@@ -0,0 +1,81 @@
+#include "../sys/schedule.h"
+#include "../lib/ll.h"
+#include "../lib/q.h"
+
+#ifdef FLAT
+static struct Task* task_list[256];
+
+static struct Scheduler scheduler = {
+ .tasks = task_list,
+};
+
+static unsigned int ntask_i = 0;
+
+void add_task(struct Task* t)
+{
+ scheduler.tasks[ntask_i] = t;
+ ntask_i += 1;
+ if (ntask_i > 256) {
+ ntask_i = 0;
+ }
+}
+
+unsigned int get_task_length(void)
+{
+ return ntask_i;
+}
+
+void execute_task(void)
+{
+ if (scheduler.tasks[ntask_i-1] != 0)
+ scheduler.tasks[ntask_i-1]->task();
+}
+#elseif LL
+static struct LL bl = {
+ .prev = 0,
+ .next = 0,
+};
+static struct Scheduler scheduler = {
+ .tasks = &bl,
+};
+#else
+static struct Q_base bq = {
+ .next = 0,
+ .last = 0,
+};
+static struct Scheduler scheduler = {
+ .tasks = &bq,
+};
+
+void add_task(struct Task* t)
+{
+ pushq(scheduler.tasks, t);
+}
+
+unsigned int get_task_length(void)
+{
+ unsigned int length = 0;
+ if (scheduler.tasks->last == 0)
+ return length;
+ else if (scheduler.tasks->next == scheduler.tasks->last)
+ return 1;
+ else {
+ struct Q* q = scheduler.tasks->next;
+ length += 1;
+ while (q->next != 0) {
+ q = q->next;
+ length += 1;
+ }
+ return length;
+ }
+}
+
+void execute_task(void)
+{
+ if (scheduler.tasks->last != 0) {
+ struct Task* tsk = (struct Task*)scheduler.tasks->next->data;
+ (tsk->task)();
+ popq(scheduler.tasks);
+ }
+}
+#endif
diff --git a/src/sys/schedule.h b/src/sys/schedule.h
new file mode 100644
index 0000000..04dad6a
--- /dev/null
+++ b/src/sys/schedule.h
@@ -0,0 +1,29 @@
+#ifndef SYS_SCHEDULE_H
+#define SYS_SCHEDULE_H
+
+struct Task {
+ unsigned char priority;
+ void (*task)(void);
+};
+
+#ifdef FLAT
+struct Scheduler {
+ struct Task** tasks;
+};
+#elseif LL
+#include "../lib/ll.h"
+struct Scheduler {
+ struct LL* tasks;
+};
+#else
+#include "../lib/q.h"
+struct Scheduler {
+ struct Q_base* tasks;
+};
+#endif
+
+void add_task(struct Task*);
+unsigned int get_task_length(void);
+void execute_task(void);
+
+#endif
--
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