i386/standford/2004/src/lab4/kern/monitor.c

   1 // Simple command-line kernel monitor useful for
   2 // controlling the kernel and exploring the system interactively.
   3
   4 #include <inc/stdio.h>
   5 #include <inc/string.h>
   6 #include <inc/pmap.h>
   7 #include <inc/assert.h>
   8 #include <inc/x86.h>
   9
  10 #include <kern/console.h>
  11 #include <kern/monitor.h>
  12 #include <kern/trap.h>
  13
  14 #define CMDBUF_SIZE     80      // enough for one VGA text line
  15
  16 struct Command {
  17         const char *name;
  18         const char *desc;
  19         void (*func)(int argc, char **argv);
  20 };
  21
  22 static struct Command commands[] = {
  23         {"help",        "Display this list of commands", mon_help},
  24         {"kerninfo",    "Display information about the kernel", mon_kerninfo},
  25 };
  26 #define NCOMMANDS (sizeof(commands)/sizeof(commands[0]))
  27
  28
  29
  30 /***** Implementations of basic kernel monitor commands *****/
  31
  32 void
  33 mon_help(int argc, char **argv)
  34 {
  35         int i;
  36
  37         for (i = 0; i < NCOMMANDS; i++)
  38                 printf("%s - %s\n", commands[i].name, commands[i].desc);
  39 }
  40
  41 void
  42 mon_kerninfo(int argc, char **argv)
  43 {
  44         extern char _start[], etext[], edata[], end[];
  45
  46         printf("Special kernel symbols:\n");
  47         printf("  _start %08x (virt)  %08x (phys)\n", _start, _start-KERNBASE);
  48         printf("  etext  %08x (virt)  %08x (phys)\n", etext, etext-KERNBASE);
  49         printf("  edata  %08x (virt)  %08x (phys)\n", edata, edata-KERNBASE);
  50         printf("  end    %08x (virt)  %08x (phys)\n", end, end-KERNBASE);
  51         printf("Kernel executable memory footprint: %dKB\n",
  52                 (end-_start+1023)/1024);
  53 }
  54
  55 void
  56 mon_backtrace(int argc, char **argv)
  57 {
  58         // Your code here.
  59 }
  60
  61
  62 /***** Kernel monitor command interpreter *****/
  63
  64 #define WHITESPACE "\t\r\n "
  65 #define MAXARGS 16
  66
  67 static void
  68 runcmd(char *buf)
  69 {
  70         int argc;
  71         char *argv[MAXARGS];
  72         int i;
  73
  74         // Parse the command buffer into whitespace-separated arguments
  75         argc = 0;
  76         argv[argc] = 0;
  77         while (1) {
  78                 // gobble whitespace
  79                 while (*buf && strchr(WHITESPACE, *buf))
  80                         *buf++ = 0;
  81                 if (*buf == 0)
  82                         break;
  83
  84                 // save and scan past next arg
  85                 if (argc == MAXARGS-1) {
  86                         printf("Too many arguments (max %d)\n", MAXARGS);
  87                         return;
  88                 }
  89                 argv[argc++] = buf;
  90                 while (*buf && !strchr(WHITESPACE, *buf))
  91                         buf++;
  92         }
  93         argv[argc] = 0;
  94
  95         // Lookup and invoke the command
  96         if (argc == 0)
  97                 return;
  98         for (i = 0; i < NCOMMANDS; i++) {
  99                 if (strcmp(argv[0], commands[i].name) == 0) {
 100                         commands[i].func(argc, argv);
 101                         return;
 102                 }
 103         }
 104         printf("Unknown command '%s'\n", argv[0]);
 105 }
 106
 107 void
 108 monitor(struct Trapframe *tf)
 109 {
 110         char *buf;
 111
 112         printf("Welcome to the JOS kernel monitor!\n");
 113         printf("Type 'help' for a list of commands.\n");
 114
 115         if (tf != NULL)
 116                 print_trapframe(tf);
 117
 118         while (1) {
 119                 buf = readline("K> ");
 120                 if (buf != NULL)
 121                         runcmd(buf);
 122         }
 123 }
 124