lesson 22, malloc

22-malloc/libc/function.h

@@ -0,0 +1 @@
+../../21-shell/libc/function.h

22-malloc/libc/mem.c

@@ -0,0 +1,33 @@
+#include "mem.h"
+
+void memory_copy(u8 *source, u8 *dest, int nbytes) {
+    int i;
+    for (i = 0; i < nbytes; i++) {
+        *(dest + i) = *(source + i);
+    }
+}
+
+void memory_set(u8 *dest, u8 val, u32 len) {
+    u8 *temp = (u8 *)dest;
+    for ( ; len != 0; len--) *temp++ = val;
+}
+
+/* This should be computed at link time, but a hardcoded
+ * value is fine for now. Remember that our kernel starts
+ * at 0x1000 as defined on the Makefile */
+u32 free_mem_addr = 0x10000;
+/* Implementation is just a pointer to some free memory which
+ * keeps growing */
+u32 kmalloc(u32 size, int align, u32 *phys_addr) {
+    /* Pages are aligned to 4K, or 0x1000 */
+    if (align == 1 && (free_mem_addr & 0xFFFFF000)) {
+        free_mem_addr &= 0xFFFFF000;
+        free_mem_addr += 0x1000;
+    }
+    /* Save also the physical address */
+    if (phys_addr) *phys_addr = free_mem_addr;
+
+    u32 ret = free_mem_addr;
+    free_mem_addr += size; /* Remember to increment the pointer */
+    return ret;
+}

22-malloc/libc/mem.h

@@ -0,0 +1,12 @@
+#ifndef MEM_H
+#define MEM_H
+
+#include "../cpu/types.h"
+
+void memory_copy(u8 *source, u8 *dest, int nbytes);
+void memory_set(u8 *dest, u8 val, u32 len);
+
+/* At this stage there is no 'free' implemented. */
+u32 kmalloc(u32 size, int align, u32 *phys_addr);
+
+#endif

22-malloc/libc/string.c

@@ -0,0 +1 @@
+../../21-shell/libc/string.c

22-malloc/libc/string.h

@@ -0,0 +1 @@
+../../21-shell/libc/string.h