1991/0625/pc/mem.h (diff list | history)

pc/mem.h on 1991/0625
1991/0625		/* * Memory and machine-specific definitions. Used in C and assembler. */
1991/0613
1991/0625		/* * Sizes */
1991/0613
1991/0625		#define BI2BY 8 /* bits per byte */ #define BI2WD 32 /* bits per word */ #define BY2WD 4 /* bytes per word */ #define BY2PG 4096 /* bytes per page */ #define WD2PG (BY2PG/BY2WD) /* words per page */ #define PGSHIFT 13 /* log(BY2PG) */ #define PGROUND(s) (((s)+(BY2PG-1))&~(BY2PG-1)) #define MAXMACH 1 /* max # cpus system can run */
1991/0613		/*
1991/0625		* Time (???) * Clock frequency is 68.3900 HZ
1991/0613		*/
1991/0625		#define HZ (68) /* clock frequency */ #define MS2HZ (1000/HZ) /* millisec per clock tick */ #define TK2SEC(t) ((t)*100/6839) /* ticks to seconds */ #define TK2MS(t) ((((ulong)(t))*100000)/6839) /* ticks to milliseconds */ #define MS2TK(t) ((((ulong)(t))*6839)/100000) /* milliseconds to ticks */
1991/0613		/*
1991/0625		* Fundamental addresses
1991/0613		*/
1991/0625		#define USERADDR 0xC0000000 #define UREGADDR (USERADDR+BY2PG-4*16)
1991/0613		/*
1991/0625		* Address spaces * * User is at 0-2GB * Kernel is at 2GB-4GB
1991/0613		*/
1991/0625		#define UZERO 0 /* base of user address space */ #define UTZERO (UZERO+BY2PG) /* first address in user text */ #define TSTKTOP USERADDR /* end of new stack in sysexec */ #define TSTKSIZ 10 #define USTKTOP (TSTKTOP-TSTKSIZ*BY2PG) /* byte just beyond user stack */ #define KZERO 0x80000000 /* base of kernel address space */ #define KTZERO KZERO /* first address in kernel text */ #define USTKSIZE (4*1024*1024) /* size of user stack */ #define MACHSIZE 4096 #define isphys(x) ((x)&KZERO)
1991/0613		/* * known segments (in GDT) and their selectors */
1991/0625		#define NULLSEG 0 /* null segment */ #define KESEG 1 /* kernel executable */ #define KDSEG 2 /* kernel data/stack */ #define UESEG 3 /* user executable */ #define UDSEG 4 /* user data/stack */ #define SYSGATE 5 /* system call gate */ #define SELGDT (0<<3) /* selector is in gdt */ #define SELLDT (1<<3) /* selector is in ldt */ #define SELECTOR(i, t, p) (((i)<<4) | (t) | (p))
1991/0613		#define NULLSEL SELECTOR(NULLSEG, SELGDT, 0) #define KESEL SELECTOR(KESEG, SELGDT, 0) #define KDSEL SELECTOR(KDSEG, SELGDT, 0) #define KSSEL SELECTOR(KDSEG, SELGDT, 0) #define UESEL SELECTOR(UESEG, SELGDT, 3) #define UDSEL SELECTOR(UDSEG, SELGDT, 3) #define USSEL SELECTOR(UDSEG, SELGDT, 3)