X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Floader.h;h=5bd981384202504e528fa968edd25814679228a0;hb=3f521b71eaf97c531bfa671b3aa2b9b971a37499;hp=2aebb0f8f3a07965bd8690c7bfc7cb81b5f3656c;hpb=8e05e0a5473ccd3988c98f95e5ec3afad225685b;p=pintos-anon

diff --git a/src/threads/loader.h b/src/threads/loader.h
index 2aebb0f..5bd9813 100644
--- a/src/threads/loader.h
+++ b/src/threads/loader.h
@@ -1,22 +1,38 @@
-#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. */
 
-/* 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.
+/* Kernel virtual address at which all physical memory is mapped.
+
+   The loader maps the 4 MB at the bottom of physical memory to
+   this virtual base address.  Later, paging_init() 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. */
+#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
 
-/* 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. */
+/* 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 /* loader.h */
+#endif /* threads/loader.h */