-#ifndef HEADER_LOADER_H
-#define HEADER_LOADER_H
+#ifndef THREADS_LOADER_H
+#define THREADS_LOADER_H
/* Constants fixed by the PC BIOS. */
#define LOADER_BASE 0x7c00 /* Physical address of loader's base. */
-#define LOADER_SIZE 0x200 /* Loader size in bytes (one disk sector). */
+#define LOADER_END 0x7e00 /* Physical address of end of loader. */
/* Physical address of kernel base. */
-#define LOADER_KERN_BASE 0x100000 /* 1 MB. */
+#define LOADER_KERN_BASE 0x20000 /* 128 kB. */
-/* The loader maps 4 MB of the start of physical memory to this
- virtual base address. Later, the kernel adds the rest of
- physical memory to the mapping.
- This must be aligned on a 4 MB boundary. */
-#define LOADER_PHYS_BASE 0xb0000000 /* 3 GB. */
+/* Kernel virtual address at which all physical memory is mapped.
+ Must be aligned on a 4 MB boundary. */
+#define LOADER_PHYS_BASE 0xc0000000 /* 3 GB. */
-/* Offsets within the loader. */
-#define LOADER_BIOS_SIG (LOADER_SIZE - 2) /* aa55 BIOS signature. */
-#define LOADER_CMD_LINE (LOADER_BIOS_SIG - 0x80) /* Kernel command line. */
-#define LOADER_RAM_PAGES (LOADER_CMD_LINE - 4) /* # of pages of RAM. */
+/* Important loader physical addresses. */
+#define LOADER_SIG (LOADER_END - LOADER_SIG_LEN) /* 0xaa55 BIOS signature. */
+#define LOADER_PARTS (LOADER_SIG - LOADER_PARTS_LEN) /* Partition table. */
+#define LOADER_ARGS (LOADER_PARTS - LOADER_ARGS_LEN) /* Command-line args. */
+#define LOADER_ARG_CNT (LOADER_ARGS - LOADER_ARG_CNT_LEN) /* Number of args. */
-#endif /* loader.h */
+/* Sizes of loader data structures. */
+#define LOADER_SIG_LEN 2
+#define LOADER_PARTS_LEN 64
+#define LOADER_ARGS_LEN 128
+#define LOADER_ARG_CNT_LEN 4
+
+/* GDT selectors defined by loader.
+ More selectors are defined by userprog/gdt.h. */
+#define SEL_NULL 0x00 /* Null selector. */
+#define SEL_KCSEG 0x08 /* Kernel code selector. */
+#define SEL_KDSEG 0x10 /* Kernel data selector. */
+
+#ifndef __ASSEMBLER__
+#include <stdint.h>
+
+/* Amount of physical memory, in 4 kB pages. */
+extern uint32_t init_ram_pages;
+#endif
+
+#endif /* threads/loader.h */