File:param.h - ikarishinjieva/unixV6-code-analyze-chs GitHub Wiki

0100 /* fundamental constants: do not change */

0101

0102

0103 #define USIZE 16 /* size of user block (*64) */

• PPDA区的大小（块数），参考内存管理

0104 #define NULL 0

0105 #define NODEV (-1)

0106 #define ROOTINO 1 /* i number of all roots */

• 超级块 的 INODE号

0107 #define DIRSIZ 14 /* max characters per directory */

0108

0109

0110 /* signals: do not change */

0111

0112

0113 #define NSIG 20

• 信号总数，参看信号系统

0114 #define SIGHUP 1 /* hangup */

0115 #define SIGINT 2 /* interrupt (rubout) */

0116 #define SIGQIT 3 /* quit (FS) */

0117 #define SIGINS 4 /* illegal instruction */

0118 #define SIGTRC 5 /* trace or breakpoint */

0119 #define SIGIOT 6 /* iot */

0120 #define SIGEMT 7 /* emt */

0121 #define SIGFPT 8 /* floating point exception */

0122 #define SIGKIL 9 /* kill */

0123 #define SIGBUS 10 /* bus error */

0124 #define SIGSEG 11 /* segmentation violation */

0125 #define SIGSYS 12 /* sys */

0126 #define SIGPIPE 13 /* end of pipe */

0127

0128 /* tunable variables */

0129

0130 #define NBUF 15 /* size of buffer cache */

0131 #define NINODE 100 /* number of in core inodes */

0132 #define NFILE 100 /* number of in core file structures */

0133 #define NMOUNT 5 /* number of mountable file systems */

0134 #define NEXEC 3 /* number of simultaneous exec’s */

• 调用exec 生成进程的 最大进程数

0135 #define MAXMEM (64*32) /* max core per process;

0136                     first number is kw */

0137 #define SSIZE 20 /* initial stack size (*64 bytes) */

0138 #define SINCR 20 /* increment of stack (*64 bytes) */

0139 #define NOFILE 15 /* max open files per process */

0140 #define CANBSIZ 256 /* max size of typewriter line */

0141 #define CMAPSIZ 100 /* size of core allocation area */

0142 #define SMAPSIZ 100 /* size of swap allocation area */

0143 #define NCALL 20 /* max simultaneous time callouts */

0144 #define NPROC 50 /* max number of processes */

0145 #define NTEXT 40 /* max number of pure texts */

0146 #define NCLIST 100 /* max total clist size */

0147 #define HZ 60/* Ticks/second of the clock */

• 60 滴答数/秒

0148

0149

0150

0151 /* priorities: do not alter much */

0152

0153

0154 #define PSWP -100

0155 #define PINOD -90

0156 #define PRIBIO -50

0157 #define PPIPE 1

0158 #define PWAIT 40

0159 #define PSLEP 90

0160 #define PUSER 100

0161

0162 /* Certain processor registers */

0163

0164 #define PS 0177776

0165 #define KL 0177560

0166 #define SW 0177570

0167

0168 /* ------------------------- */

0169

0170 /* structures to access integers : */

0171

0172

0173 /* single integer */

0174

0175 struct { int integ; };

0176

0177

0178 /* in bytes */

0179

0180 struct { char lobyte; char hibyte; };

0181

0182

0183 /* as a sequence */

0184

0185 struct { int r[];};

0186

0187

0188 /* -------------------------*/

0189

0190

0191

0192

0193

0194

0195

0196

0197

0198

0199