2 * Memory and machine-specific definitions. Used in C and assembler.
8 #define BI2BY 8 /* bits per byte */
9 #define BI2WD 32 /* bits per word */
10 #define BY2WD 4 /* bytes per word */
11 #define BY2PG 4096 /* bytes per page */
12 #define WD2PG (BY2PG/BY2WD) /* words per page */
13 #define PGSHIFT 12 /* log(BY2PG) */
14 #define PGROUND(s) (((s)+(BY2PG-1))&~(BY2PG-1))
17 * Fundamental addresses
19 #define CONFADDR 0x1200 /* info passed from boot loader */
20 #define BIOSXCHG 0x6000 /* To exchange data with the BIOS */
22 #define SELGDT (0<<3) /* selector is in gdt */
23 #define SELLDT (1<<3) /* selector is in ldt */
25 #define SELECTOR(i, t, p) (((i)<<3) | (t) | (p))
28 * fields in segment descriptors
30 #define SEGDATA (0x10<<8) /* data/stack segment */
31 #define SEGEXEC (0x18<<8) /* executable segment */
32 #define SEGTSS (0x9<<8) /* TSS segment */
33 #define SEGCG (0x0C<<8) /* call gate */
34 #define SEGIG (0x0E<<8) /* interrupt gate */
35 #define SEGTG (0x0F<<8) /* trap gate */
36 #define SEGLDT (0x02<<8) /* local descriptor table */
37 #define SEGTYPE (0x1F<<8)
39 #define SEGP (1<<15) /* segment present */
40 #define SEGPL(x) ((x)<<13) /* priority level */
41 #define SEGB (1<<22) /* granularity 1==4k (for expand-down) */
42 #define SEGD (1<<22) /* default 1==32bit (for code) */
43 #define SEGE (1<<10) /* expand down */
44 #define SEGW (1<<9) /* writable (for data/stack) */
45 #define SEGR (1<<9) /* readable (for code) */
46 #define SEGL (1<<21) /* 64 bit */
47 #define SEGG (1<<23) /* granularity 1==4k (for other) */