kalloc.[ch] from xv6, memory.[ch] containing memory probing algorithm and constants

kern/kalloc.h

@@ -0,0 +1,33 @@
+#ifndef KALLOC_KERNEL_H
+#define KALLOC_KERNEL_H
+
+/**
+ * Kernel memory allocator
+ *
+ * Allocate one 4096-byte page of physical memory.
+ * Returns a pointer that the kernel can use.
+ * Returns 0 if the memory cannot be allocated.
+ * See: kalloc.c
+ */
+void *kalloc(void);
+
+/**
+ * Kernel memory allocator
+ *
+ * Free the page of physical memory pointed at by pa,
+ * which normally should have been returned by a
+ * call to kalloc().  (The exception is when
+ * initializing the allocator; see kinit above.)
+ * See: kalloc.c
+ */
+void kfree(void *);
+
+/**
+ * Initialize kernel memory allocator
+ *
+ * Called by main() on the way to the kernel's main loop.
+ * See: kalloc.c
+ */
+void kalloc_init(void);
+
+#endif