demo: kernel 1 assignment

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-name: CI
+name: Raspberry Pi 4 CI
 
 on:
   push:

include/sched.h

@@ -66,9 +66,8 @@ typedef struct _cpu_context
     unsigned long x28;
     // unsigned long elr_el1;
     // unsigned long spsr_el1;
-    // unsigned long sp_el0;
     unsigned long fp;   /* fp is x29 */
-    unsigned long sp;   /* The task's current stack pointer */
+    unsigned long sp;   /* The task's current stack pointer - Once user space/kernel space are working: unsigned long sp_el0*/
     unsigned long pc;   /* sp is x30 */
 } CPUContext_t;
 

include/user/demo1.h

@@ -1,6 +1,8 @@
 #ifndef USER_DEMO1_H_
 #define USER_DEMO1_H_
 
+void first_user_task(void);
+void test_task(void);
 void user_task(void);
 void hello_name(char *array);
 void display_ascii_art(void);

src/demo1.c

@@ -2,6 +2,66 @@
 
 #include "peripherals/uart.h"
 #include "arm/utils.h"
+#include "task.h"
+
+void first_user_task(void)
+{
+    /* Kernel 1
+     * https://student.cs.uwaterloo.ca/~cs452/F23/assignments/k1.html
+     * 
+     * The first user task should create four instances of a test task:
+     * Two should be at a priority lower than the priority of this task (first_user_task).
+     * Two should be at a priority higher than the priority of this task (first_user_task).
+     * The lower priority tasks should be created before the higher priority tasks.
+     * On return of each `create()`, busy-wait IO should be used to print "Created: <task_id>"
+     * the terminal screen.
+     * After creating all tasks the first user task should call `exit()`, immediately after
+     * printing "FirstUserTask: exiting".
+     */
+
+    /* Two lower priority tasks */
+    int ret = task_create(3, &test_task);
+    if (ret < 0) {
+        uart_printf(CONSOLE, "Error creating task: %d\r\n", ret);
+        return;
+    }
+
+    ret = task_create(4, &test_task);
+    if (ret < 0) {
+        uart_printf(CONSOLE, "Error creating task: %d\r\n", ret);
+        return;
+    }
+
+    /* Two higher priority tasks */
+    ret = task_create(1, &test_task);
+    if (ret < 0) {
+        uart_printf(CONSOLE, "Error creating task: %d\r\n", ret);
+        return;
+    }
+
+    ret = task_create(1, &test_task);
+    if (ret < 0) {
+        uart_printf(CONSOLE, "Error creating task: %d\r\n", ret);
+        return;
+    }
+
+    uart_printf(CONSOLE, "FirstUserTask: exiting...\r\n");
+    task_exit();
+}
+
+void test_task(void)
+{
+    TaskDescriptor_t *curr = get_current_task();
+    TaskDescriptor_t *parent = curr->parent_td;
+
+    uart_printf(CONSOLE, "TestTask - tid: %d, parent_tid: %d\r\n", curr->tid, parent->tid);
+
+    task_yield();
+
+    uart_printf(CONSOLE, "TestTask - tid: %d, parent_tid: %d\r\n", curr->tid, parent->tid);
+
+    task_exit();
+}
 
 void user_task(void)
 {

src/main.c

@@ -50,31 +50,14 @@ int kmain(void)
     uart_printf(CONSOLE, "*****************************************\r\n");
     uart_printf(CONSOLE, "RTOS by roemvaar (May, 2024).\r\n");
 
-    /* Create two user tasks */
-    int ret = task_create(1, &user_task);
+    /* Kernel 1 Assignment */
+    int ret = task_create(2, &first_user_task);
     if (ret < 0) {
-        uart_printf(CONSOLE, "Error creating first task: %d\r\n", ret);
-        return ret;
-    }
-
-    ret = task_create(3, &display_ascii_art);
-    if (ret < 0) {
-        uart_printf(CONSOLE, "Error creating second task: %d\r\n", ret);
-        return ret;
-    }
-
-    ret = task_create(4, &display_ascii_art);
-    if (ret < 0) {
-        uart_printf(CONSOLE, "Error creating second task: %d\r\n", ret);
-        return ret;
-    }
-
-    ret = task_create(2, &display_ascii_art);
-    if (ret < 0) {
-        uart_printf(CONSOLE, "Error creating second task: %d\r\n", ret);
+        uart_printf(CONSOLE, "Error creating first user task: %d\r\n", ret);
         return ret;
     }
 
+    /* Debug */
     print_priority_queue();
 
     char input;