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#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_END 0x7e00 /* Physical address of end of loader. */
/* Physical address of kernel base. */
#define LOADER_KERN_BASE 0x100000 /* 1 MB. */
/* 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 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
/* 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 */
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