glo.h

一个简单的操作系统minix的核心代码

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				src/kernel/glo.h	 	 
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05000	/* Global variables used in the kernel. */
05001	
05002	/* EXTERN is defined as extern except in table.c. */
05003	#ifdef _TABLE
05004	#undef EXTERN
05005	#define EXTERN
05006	#endif
05007	
05008	/* Kernel memory. */
05009	EXTERN phys_bytes code_base;    /* base of kernel code */
05010	EXTERN phys_bytes data_base;    /* base of kernel data */
05011	
05012	/* Low level interrupt communications. */
05013	EXTERN struct proc *held_head;  /* head of queue of held-up interrupts */
05014	EXTERN struct proc *held_tail;  /* tail of queue of held-up interrupts */
05015	EXTERN unsigned char k_reenter; /* kernel reentry count (entry count less 1)*/
05016	
05017	/* Process table.  Here to stop too many things having to include proc.h. */
05018	EXTERN struct proc *proc_ptr;   /* pointer to currently running process */
05019	
05020	/* Signals. */
05021	EXTERN int sig_procs;           /* number of procs with p_pending != 0 */
05022	
05023	/* Memory sizes. */
05024	EXTERN struct memory mem[NR_MEMS];      /* base and size of chunks of memory */
05025	EXTERN phys_clicks tot_mem_size;        /* total system memory size */
05026	
05027	/* Miscellaneous. */
05028	extern u16_t sizes[];           /* table filled in by boot monitor */
05029	extern struct tasktab tasktab[];/* initialized in table.c, so extern here */
05030	extern char *t_stack[];         /* initialized in table.c, so extern here */
05031	EXTERN unsigned lost_ticks;     /* clock ticks counted outside the clock task */
05032	EXTERN clock_t tty_timeout;     /* time to wake up the TTY task */
05033	EXTERN int current;             /* currently visible console */
05034	
05035	#if (CHIP == INTEL)
05036	
05037	/* Machine type. */
05038	EXTERN int pc_at;               /* PC-AT compatible hardware interface */
05039	EXTERN int ps_mca;              /* PS/2 with Micro Channel */
05040	EXTERN unsigned int processor;  /* 86, 186, 286, 386, ... */
05041	#if _WORD_SIZE == 2
05042	EXTERN int protected_mode;      /* nonzero if running in Intel protected mode*/
05043	#else
05044	#define protected_mode  1       /* 386 mode implies protected mode */
05045	#endif
05046	
05047	/* Video card types. */
05048	EXTERN int ega;                 /* nonzero if console is EGA or VGA */
05049	EXTERN int vga;                 /* nonzero if console is VGA */
05050	
05051	/* Memory sizes. */
05052	EXTERN unsigned ext_memsize;    /* initialized by assembler startup code */
05053	EXTERN unsigned low_memsize;
05054	
05055	/* Miscellaneous. */
05056	EXTERN irq_handler_t irq_table[NR_IRQ_VECTORS];
05057	EXTERN int irq_use;             /* bit map of all in-use irq's */
05058	EXTERN reg_t mon_ss, mon_sp;    /* monitor stack */
05059	EXTERN int mon_return;          /* true if return to the monitor possible */
05060	EXTERN phys_bytes reboot_code;  /* program for the boot monitor */
05061	
05062	/* Variables that are initialized elsewhere are just extern here. */
05063	extern struct segdesc_s gdt[];  /* global descriptor table for protected mode*/
05064	
05065	EXTERN _PROTOTYPE( void (*level0_func), (void) );
05066	#endif /* (CHIP == INTEL) */
05067	
05068	#if (CHIP == M68000)
05069	/* Variables that are initialized elsewhere are just extern here. */
05070	extern int keypad;              /* Flag for keypad mode */
05071	extern int app_mode;            /* Flag for arrow key application mode */
05072	extern int STdebKey;            /* nonzero if ctl-alt-Fx detected */
05073	extern struct tty *cur_cons;    /* virtual cons currently displayed */
05074	extern unsigned char font8[];   /* 8 pixel wide font table (initialized) */
05075	extern unsigned char font12[];  /* 12 pixel wide font table (initialized) */
05076	extern unsigned char font16[];  /* 16 pixel wide font table (initialized) */
05077	extern unsigned short resolution; /* screen res; ST_RES_LOW..TT_RES_HIGH */
05078	#endif