Broken bitmap

kernel/kernel.c

@@ -25,6 +25,11 @@ void init() {
 	println("0x1000", DEFAULT_COLOR);
 	*/
 
+	block_alloc(1);
+	block_alloc(1);
+	block_alloc(2);
+	block_alloc(2);
+
 	char* strbuf = "Concat test: ";
 	char* str2 = "Works!";
 	strbuf = strcat(strbuf, str2); 

kernel/memory.c

@@ -1,4 +1,5 @@
 #include "memory.h"
+#include "../drivers/vga.h"
 
 // https://wiki.osdev.org/Page_Frame_Allocation
 // page = block
@@ -11,9 +12,11 @@
 // which is (2^32)*BLOCK_SIZE blocks
 // and with a blocksize of 1024, we git around 4.3 trillion blocks
 // which is more than enough
-int bitmap = 0;
+int bitmap = 0; 
 
-void mod_bitmap(uint block, uint bit, uint bflag) {
+#define CHECK_BITMAP(map, idx) ((map) & (1<<(idx)))
+
+void mod_bitmap(uint bit, uint bflag) {
 	// create a bitmask that will be applied to the bitmap
 	int bitmask = 1 << bit;
 
@@ -21,3 +24,16 @@ void mod_bitmap(uint block, uint bit, uint bflag) {
 	// set to bflag
 	bitmap = (((bitmap & ~bitmask)) | (bflag << bit));
 }
+
+
+int block_alloc(uint blockidx) {
+	if( CHECK_BITMAP(bitmap, blockidx) == 1 ) { // check if block is free
+		println("Alloc!", DEFAULT_COLOR);
+
+		mod_bitmap(blockidx, 0);
+
+	} else {
+		println("ERROR! Attemped to allocate non-free block.", 0x0c);
+		return -1;
+	}
+}

kernel/memory.h

@@ -1,10 +1,12 @@
 #include "../lib/types.h"
 
 #define BLOCK_SIZE 1024 // 1 KiB
+#define MAX_BLOCK_COUNT 32 // placeholder
 #define MEMSIZE_TO_BLOCKS(n) ((n*1024)/BLOCK_SIZE)
 
-enum bitmap_flag;
-
 // void init_pmm(uint map_addr, uint bsize); // Initialize physical memory manager
 
-void mod_bitmap(uint block, uint bit, uint flag);
+void mod_bitmap(uint bit, uint flag);
+
+int block_alloc(uint blockidx);
+int block_free(uint blockidx);