implements a physical memory manager... sort of, it gives an out of mem error, and variable are setting incorrectly

kernel/arch/pmm/pmm.c

@@ -1,4 +1,10 @@
 #include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+#ifdef __TESTING__
+#include <stdio.h>
+#endif
 
 #include <kernel/_kernel.h>
 #include <kernel/pmm.h>
@@ -19,25 +25,47 @@
  */
 
 #define PMM_PAGE_SIZE 4096
+#define PMM_BLOCKS_PER_BYTE 8
 
 struct pmm_mem_info {
-	uint64_t startaddr;
-	uint64_t len; // in kb
+	uint32_t startaddr;
+	uint32_t len; // in kb
 	uint32_t* bitmap;
+
+	uint32_t max_blocks;
+	uint32_t free_blocks;
+	uint32_t used_blocks;
 };
 
 #define PMM_GET_MEM_BLOCKS(x) x.len / PMM_PAGE_SIZE
 
 struct pmm_mem_info main_mem;
 
-void __pmm_set(int bit, uint32_t* bitmap)
+void pmm_set(int bit);
+void pmm_unset(int bit);
+bool pmm_test(int bit);
+int pmm_first_free(void);
+void pmm_init(void);
+void* pmm_alloc_block(void);
+void pmm_free_block(void* p);
+
+void __pmm_set(int bit, struct pmm_mem_info mem_block)
 {
-	bitmap[bit / 32] |= (1 << (bit % 32));	
+	(mem_block.bitmap)[bit / 32] |= (1 << (bit % 32));
+	mem_block.used_blocks++;
+	mem_block.free_blocks--;
 }
 
-void __pmm_unset(int bit, uint32_t* bitmap)
+void __pmm_unset(int bit, struct pmm_mem_info mem_block)
 {
-	bitmap[bit / 32] &= ~(1 << (bit % 32));
+	(mem_block.bitmap)[bit / 32] &= ~(1 << (bit % 32));
+	mem_block.used_blocks--;
+	mem_block.free_blocks--;
+}
+
+bool __pmm_test(int bit, struct pmm_mem_info mem_block)
+{
+	return (mem_block.bitmap)[bit / 32] & (1 << (bit % 32));
 }
 
 int __pmm_first_free(struct pmm_mem_info mem_block)
@@ -51,10 +79,57 @@ int __pmm_first_free(struct pmm_mem_info mem_block)
 			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_add_mem_block(uint32_t addr, int32_t len, struct pmm_mem_info* mem_block)
+{
+	mem_block->startaddr = addr;
+	mem_block->len = len;
+	mem_block->bitmap = 0;
+}
+
+void __pmm_init(struct pmm_mem_info mem_block)
+{
+	// TODO same as above
+	mem_block.used_blocks = 0;
+	mem_block.max_blocks = PMM_GET_MEM_BLOCKS(main_mem);
+	mem_block.free_blocks = mem_block.max_blocks;
+
+	memset(mem_block.bitmap, 0x0, PMM_GET_MEM_BLOCKS(mem_block) / PMM_BLOCKS_PER_BYTE); // declare all memory available
+
+#ifdef __TESTING__
+	printf("Initialized %1 blocks of memory (%1KiB available)\n", mem_block.max_blocks, mem_block.free_blocks * 4096);
+#endif
+	__pmm_set(0, mem_block); // first block must always be set
+}
+
+void* __pmm_alloc_block(struct pmm_mem_info mem_block)
+{
+	if (mem_block.free_blocks == 0) {
+		kerror("OUT OF MEMORY");
+		return 0;
+	}
+
+	int block_in_map = pmm_first_free();
+	if (block_in_map == -1) {
+		kerror("OUT OF MEMORY");
+		return 0;
+	}
+
+	__pmm_set(block_in_map, mem_block);
+
+	return (void*) (mem_block.startaddr + (block_in_map * PMM_PAGE_SIZE));
+}
+
+void __pmm_free_block(void* p, struct pmm_mem_info mem_block)
+{
+	uint64_t* addr = (uint64_t*) &p;
+	int idx = ((*addr) - mem_block.startaddr) / PMM_PAGE_SIZE;
+
+	__pmm_unset(idx, mem_block);
+}
+
 void pmm_set(int bit)
 {
 	/**
@@ -67,11 +142,58 @@ void pmm_set(int bit)
 	 *
 	 * below is merely a temporary solution
 	 */
-	__pmm_set(bit, main_mem.bitmap); 
+	__pmm_set(bit, main_mem); 
 }
 
 void pmm_unset(int bit)
 {
 	 // TODO: same as above
-	 __pmm_unset(bit, main_mem.bitmap);
+	 __pmm_unset(bit, main_mem);
 }
+
+bool pmm_test(int bit)
+{
+	// TODO: same as above
+	return __pmm_test(bit, main_mem);
+}
+
+int pmm_first_free(void) //TODO implement a free_s where it finds a series of free pages
+{
+	// TODO: same as above
+	int ret = __pmm_first_free(main_mem);
+	if (ret == -1)
+		kerror("OUT OF MEMORY");
+	return ret;
+}
+
+
+void pmm_init(void)
+{
+	// TODO same as above
+	__pmm_init(main_mem);
+}
+
+void* pmm_alloc_block(void)
+{
+	return __pmm_alloc_block(main_mem);
+}
+
+void pmm_free_block(void* p)
+{
+	__pmm_free_block(p, main_mem);
+}
+
+void pmm_add_mem_block(uint32_t addr, uint32_t len)
+{
+	// TODO: make this add to a linked list
+	__pmm_add_mem_block(addr, len, &main_mem);
+}
+
+#ifdef __TESTING__
+void print_main_mem()
+{
+	printf("Available blocks: %1\nUsed blocks: %1\nMax blocks: %1\n",
+			main_mem.free_blocks, main_mem.used_blocks, main_mem.max_blocks);
+}
+#endif
+

kernel/include/kernel/pmm.h

@@ -1,4 +1,15 @@
+#include <stdint.h>
+
 #ifndef ARCH_PMM_H
 #define ARCH_PMM_H
 
+void pmm_init(void);
+void* pmm_alloc_block(void);
+void pmm_free_block(void* p);
+void pmm_add_mem_block(uint32_t addr, uint32_t len);
+
+#ifdef __TESTING__
+void print_main_mem();
+#endif
+
 #endif

kernel/kmain.c

@@ -34,9 +34,10 @@ void verify_memmap(multiboot_info_t* mbd, uint32_t magic)
 
 		printf("Start Addr: %4 | Length: %4 | Size: %2 | Type: %d\n",
 				mmmt->addr, mmmt->len, mmmt->size, mmmt->type); 
-
-		// mmmt-> len is in bytes (according to multiboot specification0
-		// mmmt->len / 1024 == kib // block size == blocks
+		
+		if (mmmt->addr == 0x100000) {
+			pmm_add_mem_block((uint32_t) mmmt->addr, (uint32_t) mmmt->len);
+		}
 
 	}
 }
@@ -57,6 +58,13 @@ void _main(multiboot_info_t* mbd, uint32_t magic)
 	serial_initialize();
 #endif
 
+	pmm_init();
+	print_main_mem();
+
+	pmm_alloc_block();
+
+	print_main_mem();
+
 	//setup_paging();
 
 	init_kb();