+#define LOADER_PHYS_BASE 0xc0000000 /* 3 GB. */
+
+/* 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. */
+
+/* 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