ref: f0b565742993646ac2c7939e3a89f44c2515fbe6
dir: /os/boot/pc/mem.h/
/* * Memory and machine-specific definitions. Used in C and assembler. */ /* * Sizes */ #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 12 /* log(BY2PG) */ #define PGROUND(s) (((s)+(BY2PG-1))&~(BY2PG-1)) #define MAXMACH 1 /* max # cpus system can run */ /* * Time */ #define HZ (100) /* clock frequency */ #define MS2HZ (1000/HZ) /* millisec per clock tick */ #define TK2SEC(t) ((t)/HZ) /* ticks to seconds */ #define TK2MS(x) ((x)*(1000/HZ)) #define MS2TK(t) ((((ulong)(t))*HZ)/1000) /* milliseconds to ticks */ /* * Fundamental addresses */ #define IDTADDR 0x80000800 /* idt */ #define APBOOTSTRAP 0x80001000 /* AP bootstrap code */ #define CONFADDR 0x80001200 /* info passed from boot loader */ #define CPU0PDB 0x80002000 /* bootstrap processor PDB */ #define CPU0PTE 0x80003000 /* bootstrap processor PTE's for 0-4MB */ #define MACHADDR 0x80004000 /* as seen by current processor */ #define CPU0MACH 0x80005000 /* Mach for bootstrap processor */ #define BIOSXCHG 0x80006000 /* To exchange data with the BIOS */ #define MACHSIZE (BY2PG*8) /* stack size */ /* * Address spaces * * Kernel is at 2GB-4GB */ #define KZERO 0x80000000 /* base of kernel address space */ #define KTZERO KZERO /* first address in kernel text */ #define ROMBIOS (KZERO|0xF0000) /* * known 80386 segments (in GDT) and their selectors */ #define NULLSEG 0 /* null segment */ #define KDSEG 1 /* kernel data/stack */ #define KESEG 2 /* kernel executable */ #define UDSEG 3 /* user data/stack */ #define UESEG 4 /* user executable */ #define SYSGATE 5 /* system call gate */ #define TSSSEG 6 /* task segment */ #define SELGDT (0<<3) /* selector is in gdt */ #define SELLDT (1<<3) /* selector is in ldt */ #define SELECTOR(i, t, p) (((i)<<3) | (t) | (p)) #define NULLSEL SELECTOR(NULLSEG, SELGDT, 0) #define KESEL SELECTOR(KESEG, SELGDT, 0) #define KDSEL SELECTOR(KDSEG, SELGDT, 0) #define UESEL SELECTOR(UESEG, SELGDT, 3) #define UDSEL SELECTOR(UDSEG, SELGDT, 3) #define TSSSEL SELECTOR(TSSSEG, SELGDT, 0) /* * fields in segment descriptors */ #define SEGDATA (0x10<<8) /* data/stack segment */ #define SEGEXEC (0x18<<8) /* executable segment */ #define SEGTSS (0x9<<8) /* TSS segment */ #define SEGCG (0x0C<<8) /* call gate */ #define SEGIG (0x0E<<8) /* interrupt gate */ #define SEGTG (0x0F<<8) /* task gate */ #define SEGTYPE (0x1F<<8) #define SEGP (1<<15) /* segment present */ #define SEGPL(x) ((x)<<13) /* priority level */ #define SEGB (1<<22) /* granularity 1==4k (for expand-down) */ #define SEGG (1<<23) /* granularity 1==4k (for other) */ #define SEGE (1<<10) /* expand down */ #define SEGW (1<<9) /* writable (for data/stack) */ #define SEGR (1<<9) /* readable (for code) */ #define SEGD (1<<22) /* default 1==32bit (for code) */ /* * virtual MMU */ #define PTEMAPMEM (1024*1024) /* ??? */ #define SEGMAPSIZE 16 /* ??? */ #define PTEPERTAB (PTEMAPMEM/BY2PG) /* ??? */ #define PPN(x) ((x)&~(BY2PG-1)) /* * physical MMU */ #define PTEVALID (1<<0) #define PTEUNCACHED 0 /* everything is uncached */ #define PTEWRITE (1<<1) #define PTERONLY (0<<1) #define PTEKERNEL (0<<2) #define PTEUSER (1<<2) #define PTESIZE (1<<7) /* * flag register bits that we care about */ #define IFLAG 0x200