shell.c

/***********************************************************************************
 * @file        shell.c                                                            *
 * @author      Matt Ricci                                                         *
 * @addtogroup  Shell                                                              *
 *                                                                                 *
 * @todo Add commands to buffer to allow managing shell history for frontend       *
 ***********************************************************************************/
 
#include "shell.h"
 
#include "devicelist.h"
 
extern uint32_t __shell_vector_start;
extern uint32_t __shell_vector_end;
 
/* =============================================================================== */
void vShellExec(void *argument) {
  ShellTaskParams params = *(ShellTaskParams *)argument;
 
  for (;;) {
    params.shell->run(params.shell, params.str);
 
    // Remove handle from shell first to prevent
    // nullptr dereference in Shell_clear
    params.shell->taskHandle = NULL;
 
    // Delete task and end thread
    vTaskDelete(NULL);
  }
}
 
/* =============================================================================== */
int Shell_init(Shell *shell) {
  shell->usb     = *(UART_t *)DeviceList_getDeviceHandle(DEVICE_UART_USB).device;
  shell->help    = Shell_help;
  shell->run     = Shell_run;
  shell->runTask = Shell_runTask;
  shell->clear   = Shell_clear;
 
  // TODO:
  // Error checking to determine if any shell programs exist or vector overflow
  // occurred.
 
  return 0;
}
 
/* =============================================================================== */
void Shell_help(Shell *shell) {
  shell->usb.print(&shell->usb, "Use `help [name]` for more information on a specific command\n\r");
  shell->usb.print(&shell->usb, "The following commands are currently available:\n\r");
  for (uint32_t *i = (uint32_t *)&__shell_vector_start; i < (uint32_t *)&__shell_vector_end; i++) {
    ShellProgramHandle_t *handle = (ShellProgramHandle_t *)*i;
    if (strcmp(handle->name, "")) {
      shell->usb.print(&shell->usb, ":");
      shell->usb.print(&shell->usb, handle->name);
      shell->usb.print(&shell->usb, "\n\r");
    }
  }
}
 
/* =============================================================================== */
void Shell_run(Shell *shell, uint8_t *programName) {
  char *token = strtok((char *)programName, " ");
  char *flags = strchr(token, '\0') + 1;
 
  // Register programs in vector to shell
  for (uint32_t *i = (uint32_t *)&__shell_vector_start; i < (uint32_t *)&__shell_vector_end; i++) {
    // Dereference memory location and cast to program handle pointer
    ShellProgramHandle_t *handle = (ShellProgramHandle_t *)*i;
    // Iterate shell vector and execute function from handle with matching name (if any)
    if (!strcmp(handle->name, programName)) {
      handle->exec(shell, flags);
      return; // Early exit if program is found
    }
  }
 
  // Print help string if no matching command is found
  shell->usb.print(&shell->usb, (char *)programName);
  shell->usb.print(&shell->usb, ": command not recognized. Run `help` for a list of available commands\n\r");
}
 
/* =============================================================================== */
void Shell_runTask(Shell *shell, uint8_t *str) {
 
  static ShellTaskParams params;
  params.shell = shell;
  params.str   = str;
 
  // Create new task to parse and execute shell program
  xTaskCreate(
      vShellExec,
      "ShellProgram",
      256,
      (void *)&params,
      configMAX_PRIORITIES - 6,
      &shell->taskHandle
  );
}
 
/* =============================================================================== */
bool Shell_clear(Shell *shell) {
  shell->usb.print(&shell->usb, CMD_CLEAR);
  // Delete any running task
  if (shell->taskHandle != NULL)
    vTaskDelete(shell->taskHandle);
  return true;
}