implements first free mem block

kernel/arch/pmm/pmm.c

@@ -1,3 +1,6 @@
+#include <stdint.h>
+
+#include <kernel/_kernel.h>
 #include <kernel/pmm.h>
 
 /**
@@ -37,11 +40,19 @@ void __pmm_unset(int bit, uint32_t* bitmap)
 	bitmap[bit / 32] &= ~(1 << (bit % 32));
 }
 
-void __pmm_first_free(struct pmm_mem_info mem_block)
+int __pmm_first_free(struct pmm_mem_info mem_block)
 {
 	for (uint32_t i = 0; i < PMM_GET_MEM_BLOCKS(mem_block) / 32; i++) {
-
+		if (mem_block.bitmap[i] == 0xFFFFFFFF) // this segment is full
+			continue;
+		for (int j = 0; j < 32; j++) {
+			if (mem_block.bitmap[i] & (1 << j))
+				continue; // this page is used 
+			return (i * 32) + j; // i * 32 is the chunk of 32, plus j to get to the page in the chunk
+		}
 	}
+	kwarn("OUT OF MEMORY");
+	return -1;
 }
 
 void pmm_set(int bit)