Properly detect memory using atags and add it to the memory-management subsystem

include/atags.h

@@ -0,0 +1,48 @@
+#ifndef ATAGS_H
+#define ATAGS_H
+
+#include <types.h>
+
+#define ATAG_NONE	0x00000000
+#define ATAG_CORE	0x54410001
+#define ATAG_MEM	0x54410002
+#define ATAG_VIDEOTEXT	0x54410003
+#define ATAG_RAMDISK	0x54410004
+#define ATAG_INITRD2	0x54420005
+#define ATAG_SERIAL	0x54410006
+#define ATAG_REVISION	0x54410007
+#define ATAG_VIDEOLFB	0x54410008
+#define ATAG_CMDLINE	0x54410009
+
+struct atag_core {
+	uint32 flags;		/* bit 0 = read-only */
+	uint32 pagesize;	/* systems page size (usually 4k) */
+	uint32 rootdev;		/* root device number */
+};
+
+struct atag_mem {
+	uint32 size;	/* size of the area */
+	uint32 start;	/* physical start address */
+};
+
+struct atag {
+	uint32 size; /* Size of tag in words (includes entire struct) */
+	uint32 tag;
+	union {
+		struct atag_core	core;
+		struct atag_mem		mem;
+//		struct atag_videotext	videotext;
+//		struct atag_ramdisk	ramdisk;
+//		struct atag_initrd2	initrd2;
+//		struct atag_serialnr	serialnr;
+//		struct atag_revision	revision;
+//		struct atag_videolfb	videolfb;
+//		struct atag_cmdline	cmdline;
+	} data;
+};
+
+#define atags_first_mem_region(atag) _atags_mem_region(atag, 1)
+#define atags_next_mem_region(atag) _atags_mem_region(atag, 0)
+int _atags_mem_region(struct atag **mem_header, int initialize);
+
+#endif /* ATAGS_H */

include/mmu.h

@@ -1,8 +1,9 @@
 #ifndef MMU_H
 #define MMU_H
 
-extern unsigned int *kernel_start_phys, *kernel_start_virt, *kernel_end_phys, *kernel_end_virt;
+#include <types.h>
 
 void mmu_reinit();
+void declare_memory_region(void *lower, void *upper);
 
 #endif /* MMU_H */

include/types.h

@@ -0,0 +1 @@
+typedef unsigned int uint32;