com32/elflink/test_com32.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <console.h>
   4 #include <string.h>
   5
   6 #include <sys/module.h>
   7 #include <sys/exec.h>
   8
   9 #define INFO_PRINT(fmt, args...)        printf("[COM32] " fmt, ##args)
  10
  11 #define MAX_COMMAND_SIZE        80      // Maximum size of the cmd line
  12 #define COMMAND_DELIM           " \t\n" // Whitespace delimiters
  13 #define MAX_COMMAND_ARGS        (MAX_COMMAND_SIZE/2)    // Maximum argument count for
  14                                                                                                  // program execution
  15
  16 /**
  17  * print_help - Display usage instructions on the screen.
  18  */
  19 static void print_help(void)
  20 {
  21     printf("List of available commands:\n");
  22     printf("exit - exits the program\n");
  23     printf("help - shows this message\n");
  24     printf("load <library>... - loads the libraries into the environment\n");
  25     printf("spawn <executable> <args> - launches an executable module\n");
  26     printf
  27         ("unload <library>... - unloads the libraries from the environment\n");
  28     printf("list - prints the currently loaded modules\n");
  29 }
  30
  31 /**
  32  * print_prompt - Display the command prompt.
  33  */
  34 static void print_prompt(void)
  35 {
  36     printf("\nelflink> ");
  37 }
  38
  39 /**
  40  * read_command - Read a new command from the standard input.
  41  * @cmd: the buffer to store the command
  42  * @size: the maximum size of the string that can be stored in the buffer
  43  *
  44  * If the command is larger than the specified size, it is truncated.
  45  */
  46 static void read_command(char *cmd, int size)
  47 {
  48     char *nl = NULL;
  49     fgets(cmd, size, stdin);
  50
  51     // Strip the newline
  52     nl = strchr(cmd, '\n');
  53
  54     if (nl != NULL)
  55         *nl = '\0';
  56 }
  57
  58 /**
  59  * process_spawn - Handles the execution of a 'spawn' command.
  60  *
  61  * The command line is in the internal buffer of strtok.
  62  */
  63 static void process_spawn(void)
  64 {
  65     // Compose the command line
  66     char **cmd_line = malloc((MAX_COMMAND_ARGS + 1) * sizeof(char *));
  67     int argc = 0, result;
  68     char *crt_arg;
  69
  70     do {
  71         crt_arg = strtok(NULL, COMMAND_DELIM);
  72         if (crt_arg != NULL && strlen(crt_arg) > 0) {
  73             cmd_line[argc] = crt_arg;
  74             argc++;
  75         } else {
  76             break;
  77         }
  78     } while (argc < MAX_COMMAND_ARGS);
  79
  80     cmd_line[argc] = NULL;
  81
  82     if (cmd_line[0] == NULL) {
  83         printf("You must specify an executable module.\n");
  84     } else {
  85         result = spawnv(cmd_line[0], cmd_line);
  86
  87         printf("Spawn returned %d\n", result);
  88     }
  89
  90     free(cmd_line);
  91 }
  92
  93 /**
  94  * process_library - Handles the execution of the 'load' and 'unload' commands.
  95  * @load: contains 1 if the libraries are to be loaded, 0 for unloading.
  96  *
  97  * The command line is in the internal buffer of strtok.
  98  */
  99 static void process_library(int load)
 100 {
 101     char *crt_lib;
 102     int result;
 103
 104     while ((crt_lib = strtok(NULL, COMMAND_DELIM)) != NULL) {
 105         if (strlen(crt_lib) > 0) {
 106             if (load)
 107                 result = load_library(crt_lib);
 108             else
 109                 result = unload_library(crt_lib);
 110
 111             if (result == 0) {
 112                 printf("Library '%s' %sloaded successfully.\n", crt_lib,
 113                        load ? "" : "un");
 114             } else {
 115                 printf("Could not %sload library '%s': error %d\n",
 116                        load ? "" : "un", crt_lib, result);
 117             }
 118         }
 119     }
 120 }
 121
 122 /**
 123  * process_list - Handles the execution of the 'list' command.
 124  *
 125  */
 126 static void process_list(void)
 127 {
 128     struct elf_module *module;
 129     struct module_dep *crt_dep;
 130
 131     for_each_module(module) {
 132         printf("%s (%dK, %s, %s) : ", module->name, module->module_size >> 10,
 133                module->shallow ? "shallow" : "regular",
 134                module->main_func == NULL ? "library" : "program");
 135
 136         list_for_each_entry(crt_dep, &module->required, list) {
 137             printf("%s ", crt_dep->module->name);
 138         }
 139
 140         printf("\n");
 141     }
 142 }
 143
 144 /**
 145  * process_command - Recognizes the requested command and executes it.
 146  * @cmd: the command to be executed.
 147  *
 148  * Returns 1 if the command was 'exit', 0 otherwise.
 149  */
 150 static int process_command(char *cmd)
 151 {
 152     char *cmd_name;
 153
 154     cmd_name = strtok(cmd, COMMAND_DELIM);
 155
 156     if (strcmp(cmd_name, "exit") == 0) {
 157         printf("Goodbye!\n");
 158         return 1;
 159     } else if (strcmp(cmd_name, "help") == 0) {
 160         print_help();
 161     } else if (strcmp(cmd_name, "load") == 0) {
 162         process_library(1);
 163     } else if (strcmp(cmd_name, "spawn") == 0) {
 164         process_spawn();
 165     } else if (strcmp(cmd_name, "unload") == 0) {
 166         process_library(0);
 167     } else if (strcmp(cmd_name, "list") == 0) {
 168         process_list();
 169     } else {
 170         printf("Unknown command. Type 'help' for a list of valid commands.\n");
 171     }
 172
 173     return 0;
 174 }
 175
 176 /**
 177  * The entry point of 'test_com32' COM module.
 178  */
 179 int main(int argc, char **argv)
 180 {
 181     int done = 0;
 182     int res;
 183     char command[MAX_COMMAND_SIZE] = { 0 };
 184
 185     // Open a standard r/w console
 186     openconsole(&dev_stdcon_r, &dev_stdcon_w);
 187
 188     res = exec_init();
 189     if (res != 0) {
 190         printf("Failed to initialize the execution environment.\n");
 191         return res;
 192     } else {
 193         printf("Execution environment initialized successfully.\n");
 194     }
 195
 196     printf("\nFor a list of available commands, type 'help'.\n");
 197
 198     do {
 199         print_prompt();
 200         read_command(command, MAX_COMMAND_SIZE);
 201         done = process_command(command);
 202
 203     } while (!done);
 204
 205     exec_term();
 206
 207     return 0;
 208 }