-#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. */
This must be aligned on a 4 MB boundary. */
#define LOADER_PHYS_BASE 0xc0000000 /* 3 GB. */
-/* Offsets within the loader. */
-#define LOADER_BIOS_SIG (LOADER_END - 2) /* 0xaa55 BIOS signature. */
-#define LOADER_CMD_LINE_LEN 0x80 /* Command line length. */
-#define LOADER_CMD_LINE (LOADER_BIOS_SIG - LOADER_CMD_LINE_LEN)
- /* 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_ARGS (LOADER_SIG - LOADER_ARGS_LEN) /* Command-line args. */
+#define LOADER_ARG_CNT (LOADER_ARGS - LOADER_ARG_CNT_LEN) /* Number of args. */
+#define LOADER_RAM_PGS (LOADER_ARG_CNT - LOADER_RAM_PGS_LEN) /* # RAM pages. */
-#endif /* loader.h */
+/* Sizes of loader data structures. */
+#define LOADER_SIG_LEN 2
+#define LOADER_ARGS_LEN 128
+#define LOADER_ARG_CNT_LEN 4
+#define LOADER_RAM_PGS_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. */
+
+#endif /* threads/loader.h */