create kmalloc and km_init

1 files changed, 30 insertions, 1 deletions

diff --git a/kernel/mem.c b/kernel/mem.c
index 3a0b19b..840a3b7 100644
--- a/kernel/mem.c
+++ b/kernel/mem.c
@@ -3,10 +3,31 @@
 #include <dtb.h>
 #include <common.h>
 
+static struct page *free_list;
+
 void* kmalloc(size_t size) {
-    return (void*)size;
+    struct page *page = free_list;
+    while (page != NULL && page->size < size && page->status != MEMPAGE_FREE) {
+        page = page->next;
+    }
+    if (page == NULL)
+        return NULL;
+
+    size_t combined_size = size + sizeof(struct page);
+    struct page *next = (struct page *)((void *)page + combined_size);
+    next->next = page->next;
+    next->size = page->size - combined_size;
+    next->status = MEMPAGE_FREE;
+
+    page->status = MEMPAGE_USED;
+    next->size = combined_size;
+    next->next = NULL;
+
+    return (void *)page + sizeof(struct page);
 }
 
+
+
 void* memcpy(void *to, const void *from, size_t size) {
     char *dest = (char *)to;
     const char *src = (const char *)from;
@@ -18,3 +39,11 @@ void* memcpy(void *to, const void *from, size_t size) {
     return dest;
 }
 
+void km_init(struct mem_info *info) {
+    struct page *base = (struct page *)info->start;
+    base->next = NULL;
+    base->size = info->size - sizeof(struct page);
+    base->status = MEMPAGE_FREE;
+
+    free_list = base;
+}