temp12

Author: nickchan2

kernel/cortex_m4.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <stddef.h>
+
+// Interrupt control and state register
+static volatile size_t *const cm4_icsr = (volatile size_t *)0xE000ED04U;
+
+static const size_t cm4_icsr_pendsvset_mask = 1U << 28U;
+
+// Floating point context control register
+static volatile size_t *const fpcsr = (volatile size_t *)0xE000EF34U;
+
+static const size_t fpcsr_aspen_mask = 1U << 31U;
+static const size_t fpcsr_lspen_mask = 1U << 30U;
+
+// Return to thread mode, use PSP, no FP context
+static const size_t cm4_exc_return_thread_psp_nofp = 0xFFFFFFFDU;
+
+static const size_t cm4_epsr_thumb_mask = 1U << 24U;
+
+static void cm4_enable_irq(void) {
+    __asm volatile("cpsie i");
+}
+
+// Equivalent to writing 0 to PRIMASK, which raises the execution priority to
+// 0, effectively disabling all interrupts. Note that Hardfault, NMI, and
+// Reset exceptions still have higher priority.
+static void cm4_disable_irq(void) {
+    __asm volatile("cpsid i");
+}

kernel/dll.h

@@ -0,0 +1,71 @@
+#pragma once
+
+#include "rtos.h"
+
+#include <stdbool.h>
+#include <stddef.h>
+
+static bool dll_is_empty(const rtos_dll_t *dll) {
+    return dll->head == NULL;
+}
+
+static rtos_task_t *dll_pop_front(rtos_dll_t *dll) {
+    assert(dll->head != NULL);
+    rtos_task_t *const popped = dll->head;
+    if (popped->next == NULL) {
+        dll->tail = NULL;
+    } else {
+        popped->next->prev = NULL;
+    }
+    dll->head = popped->next;
+    popped->prev = NULL;
+    popped->next = NULL;
+    return popped;
+}
+
+static void dll_push_front(rtos_dll_t *dll, rtos_task_t *task) {
+    if (dll->head == NULL) {
+        dll->head = task;
+        dll->tail = task;
+        task->prev = NULL;
+        task->next = NULL;
+    } else {
+        dll->head->prev = task;
+        task->next = dll->head;
+        dll->head = task;
+        task->prev = NULL;
+    }
+}
+
+static void dll_push_back(rtos_dll_t *dll, rtos_task_t *task) {
+    if (dll->head == NULL) {
+        dll->head = task;
+        dll->tail = task;
+        task->prev = NULL;
+        task->next = NULL;
+    } else {
+        dll->tail->next = task;
+        task->prev = dll->tail;
+        task->next = NULL;
+        dll->tail = task;
+    }
+}
+
+static void dll_insert_ascending(rtos_dll_t *dll, rtos_task_t *task) {
+    rtos_task_t *ptr = dll->head;
+    while (ptr != NULL && ptr->wake_time < task->wake_time) {
+        ptr = ptr->next;
+    }
+    if (ptr == NULL) {
+        dll_push_back(dll, task);
+    } else {
+        if (ptr->prev == NULL) {
+            dll->head = task;
+        } else {
+            ptr->prev->next = task;
+        }
+        task->prev = ptr->prev;
+        task->next = ptr;
+        ptr->prev = task;
+    }
+}