idk we're trying out pmm

kernel/arch/paging/paging.c

@@ -6,50 +6,3 @@
 
 //extern uint32_t endkernel; // found in link.ld
 
-/**
- * The page table must be page aligned (aligned at 4KiB)
- *
- *
- * This is a temporary solution, as we want a page frame allocator, to properly get page frames.. but this works for now
- */
-uint32_t page_directory[PAGE_DIRECTORY_ENTRIES] __attribute__((aligned(4096)));
-
-uint32_t first_page_table[PAGE_TABLE_ENTRIES] __attribute__((aligned(4096)));
-
-void setup_page_table(void)
-{
-	uint32_t i;
-	for (i = 0; i < PAGE_TABLE_ENTRIES; i++) {
-		first_page_table[i] = (i * 0x1000) | 3; // supervisor, r/w, present
-	}
-	puts("test");
-}
-
-void setup_page_dir(void)
-{
-	setup_page_table();
-	/**
-	 * Now that we have a page directory, we need to blank it.
-	 *
-	 * The page directory should have exactly 1024 entries. We will set each entry to not present, so that the if the
-	 * MMU looks for that page table, it will see that it is not there yet.
-	 */
-	int i;
-	for (i = 0; i < PAGE_DIRECTORY_ENTRIES; i++) {
-		// This sets the following flags to the pages:
-		// 	Supervisor: Only kernel-mode can access them
-		// 	Write Enabled: It can be both read from and written to
-		// 	Not Present: The page table is not present
-		page_directory[i] = 0x00000002;
-	}
-
-	page_directory[0] = ((uint32_t) first_page_table) | 3;
-}
-
-void setup_paging(void)
-{
-	setup_page_dir();
-
-	load_page_directory(page_directory);
-	enable_paging();
-}

kernel/arch/pmm/pmm.c

@@ -0,0 +1,66 @@
+#include <kernel/pmm.h>
+
+/**
+ * What i want to do is create a linked list of all the memory structures
+ *
+ * Theres one at the very start of the memory
+ *
+ * one at 1MB
+ *
+ * and then one provided by ram.
+ *
+ *
+ * So the idea is to create a way to access memory through this such that,
+ * when you give a bit block number, it'll go through the first item in the linked list, if the block is out of that range, it 
+ * traverses to the next node, tries to find it there, and then continues until it either runs out of memory, or finds a location
+ */
+
+#define PMM_PAGE_SIZE 4096
+
+struct pmm_mem_info {
+	uint64_t startaddr;
+	uint64_t len; // in kb
+	uint32_t* bitmap;
+};
+
+#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)
+{
+	bitmap[bit / 32] |= (1 << (bit % 32));	
+}
+
+void __pmm_unset(int bit, uint32_t* bitmap)
+{
+	bitmap[bit / 32] &= ~(1 << (bit % 32));
+}
+
+void __pmm_first_free(struct pmm_mem_info mem_block)
+{
+	for (uint32_t i = 0; i < PMM_GET_MEM_BLOCKS(mem_block) / 32; i++) {
+
+	}
+}
+
+void pmm_set(int bit)
+{
+	/**
+	 * Here we want to calculate if the bit is over the length
+	 * subtract the length and bit amount so that we compensate for the bit map
+	 *
+	 * i.e. (length / 4096) == amount of blocks in that specific mem region
+	 * if (bit > amt of blocks), 
+	 * go to next node, subtract amt of blocks from bit, and pass that
+	 *
+	 * below is merely a temporary solution
+	 */
+	__pmm_set(bit, main_mem.bitmap); 
+}
+
+void pmm_unset(int bit)
+{
+	 // TODO: same as above
+	 __pmm_unset(bit, main_mem.bitmap);
+}

kernel/include/kernel/_kernel.h

@@ -7,6 +7,5 @@ void kwarn(const char*);
 
 void kinfo(const char*);
 
-
 #endif
 

kernel/include/kernel/paging.h

@@ -3,14 +3,4 @@
 #ifndef ARCH_PAGING_H
 #define ARCH_PAGING_H
 
-#define PAGE_TABLE_ENTRIES 1024
-#define PAGE_DIRECTORY_ENTRIES 1024
-
-void load_page_directory(uint32_t*);
-
-void enable_paging();
-
-
-void setup_paging(void);
-
 #endif

kernel/include/kernel/pmm.h

@@ -0,0 +1,20 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+
+#ifndef ARCH_PMM_H
+#define ARCH_PMM_H
+
+#define PMM_BLOCKS_PER_BYTE 8 // This is for the Bitmap
+#define PMM_BLOCK_SIZE 4096 // 4KiB
+#define PMM_BLOCK_ALIGN (PMM_BLOCK_SIZE) // must be aligned at 4KiB
+
+void set_grub_mem_map(uint32_t addr, uint32_t len);
+uint32_t pmm_get_block_count(void);
+
+int pmm_first_free(void);
+int pmm_first_free_s(size_t pages);
+
+void pmm_init(size_t mem_size, uint32_t* bitmap);
+
+#endif

kernel/kmain.c

@@ -12,6 +12,7 @@
 #include <kernel/x86/keyb.h>
 #include <kernel/x86/pit.h>
 #include <kernel/x86/pci.h>
+#include <kernel/pmm.h>
 
 #include "multiboot.h"
 
@@ -19,44 +20,32 @@ void verify_memmap(multiboot_info_t* mbd, uint32_t magic)
 {
 	if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
 		panic("Invalid magic number!");
-	else
-		printf("%2\n", magic);
 
 	if (!(mbd->flags >> 6 & 0x1))
 		panic("Invalid memory map given by GRUB bootloader!");
 
-#ifdef __TESTING__
+	if (!(mbd->flags & (1 << 0)))
+		panic("Memory info not passed to kernel!");
+
 	puts("Printing available memory map...");
 	uint32_t i;
 	for (i = 0; i < mbd->mmap_length; i += sizeof(multiboot_memory_map_t)) {
 		multiboot_memory_map_t* mmmt = (multiboot_memory_map_t*) (mbd->mmap_addr + i);
 
-		printf("Start Addr: %4 | Length: %4 | Size: %2 | Type: ",
-				mmmt->addr, mmmt->len, mmmt->size);
-		switch (mmmt->type) {
-			case MULTIBOOT_MEMORY_AVAILABLE:
-				puts("Available");
-				break;
-			case MULTIBOOT_MEMORY_RESERVED:
-				puts("Reserved");
-				break;
-			case MULTIBOOT_MEMORY_ACPI_RECLAIMABLE:
-				puts("ACPI Reclaimable");
-				break;
-			case MULTIBOOT_MEMORY_NVS:
-				puts("NVS");
-				break;
-			case MULTIBOOT_MEMORY_BADRAM:
-				puts("Bad ram");
-				break;
-			default:
-				puts("Unknown");
-				break;
+		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->type == MULTIBOOT_MEMORY_AVAILABLE && (mmmt->addr == 0x100000)) {
+			// This is the main mem address we want
+			// TODO: this is probably flaky, so i want to find a better and more reliable way to do this
+			set_grub_mem_map(mmmt->addr, mmmt->len);		
+		}
 	}
 
-		// if (mmmt->type == MULTIBOOT_MEMORY_AVAILABLE) -> DO SOMETHING
-	}
-#endif
+	printf("%2 %2\n", mbd->mem_lower, mbd->mem_upper);
 }
 
 void _main(multiboot_info_t* mbd, uint32_t magic)
@@ -65,6 +54,7 @@ void _main(multiboot_info_t* mbd, uint32_t magic)
 	terminal_initialize();
 	serial_initialize();
 #endif
+	printf("%2, %2\n", mbd->mem_lower, mbd->mem_upper);
 
 	verify_memmap(mbd, magic);	
 
@@ -76,7 +66,7 @@ void _main(multiboot_info_t* mbd, uint32_t magic)
 	serial_initialize();
 #endif
 
-	setup_paging();
+	//setup_paging();
 
 	init_kb();