utility/crossystem.c

/* Copyright 2012 The ChromiumOS Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 *
 * Chrome OS firmware/system interface utility
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "crossystem.h"

/* Flags for Param */
#define IS_STRING      0x01  /* String (not present = integer) */
#define CAN_WRITE      0x02  /* Writable (not present = read-only */
#define NO_PRINT_ALL   0x04  /* Don't print contents of parameter when
                              * doing a print-all */

typedef struct Param {
  const char* name;  /* Parameter name */
  int flags;         /* Flags (see above) */
  const char* desc;  /* Human-readable description */
  const char* format; /* Format string, if non-NULL and 0==is_string*/
} Param;

/* List of parameters, terminated with a param with NULL name */
const Param sys_param_list[] = {
  {"act_fwver", 0, "Active firmware version", "0x%08x"},
  {"act_kernver", 0, "Active kernel version", "0x%08x"},
  {"arch", IS_STRING, "Platform architecture"},
  {"backup_nvram_request", CAN_WRITE,
   "Backup the nvram somewhere at the next boot. Cleared on success."},
  {"battery_cutoff_request", CAN_WRITE,
   "Cut off battery and shutdown on next boot"},
  {"block_devmode", CAN_WRITE, "Block all use of developer mode"},
  {"board_id", 0, "Board hardware revision number"},
  {"clear_tpm_owner_done", CAN_WRITE, "Clear TPM owner done"},
  {"clear_tpm_owner_request", CAN_WRITE, "Clear TPM owner on next boot"},
  {"cros_debug", 0, "OS should allow debug features"},
  {"dbg_reset", CAN_WRITE, "Debug reset mode request"},
  {"debug_build", 0, "OS image built for debug features"},
  {"dev_boot_altfw", CAN_WRITE, "Enable developer mode alternate bootloader"},
  {"dev_boot_signed_only", CAN_WRITE,
   "Enable developer mode boot only from official kernels"},
  {"dev_boot_usb", CAN_WRITE,
   "Enable developer mode boot from external disk (USB/SD)"},
  {"dev_default_boot", IS_STRING|CAN_WRITE,
   "Default boot from disk, altfw or usb"},
  {"dev_enable_udc", CAN_WRITE, "Enable USB Device Controller"},
  {"devsw_boot", 0, "Developer switch position at boot"},
  {"devsw_cur",  0, "Developer switch current position"},
  {"diagnostic_request", CAN_WRITE, "Request diagnostic rom run on next boot"},
  {"disable_dev_request", CAN_WRITE, "Disable virtual dev-mode on next boot"},
  {"ecfw_act", IS_STRING, "Active EC firmware"},
  {"post_ec_sync_delay", CAN_WRITE,
   "Short delay after EC software sync (persistent, writable, eve only)"},
  {"fw_prev_result", IS_STRING, "Firmware result of previous boot"},
  {"fw_prev_tried", IS_STRING, "Firmware tried on previous boot (A or B)"},
  {"fw_result", IS_STRING|CAN_WRITE, "Firmware result this boot"},
  {"fw_tried", IS_STRING, "Firmware tried this boot (A or B)"},
  {"fw_try_count", CAN_WRITE, "Number of times to try fw_try_next"},
  {"fw_try_next", IS_STRING|CAN_WRITE, "Firmware to try next (A or B)"},
  {"fw_vboot2", 0, "1 if firmware was selected by vboot2 or 0 otherwise"},
  {"fwb_tries", CAN_WRITE, "Try firmware B count"},
  {"fwid", IS_STRING, "Active firmware ID"},
  {"fwupdate_tries", CAN_WRITE,
   "Times to try OS firmware update (inside kern_nv)"},
  {"hwid", IS_STRING, "Hardware ID"},
  {"inside_vm", 0, "Running in a VM?"},
  {"kern_nv", 0, "Non-volatile field for kernel use", "0x%04x"},
  {"kernel_max_rollforward", CAN_WRITE, "Max kernel version to store into TPM",
   "0x%08x"},
  {"kernkey_vfy", IS_STRING, "Type of verification done on kernel keyblock"},
  {"loc_idx", CAN_WRITE, "Localization index for firmware screens"},
  {"mainfw_act", IS_STRING, "Active main firmware"},
  {"mainfw_type", IS_STRING, "Active main firmware type"},
  {"minios_priority", IS_STRING|CAN_WRITE,
   "miniOS image to try first (A or B)"},
  {"nvram_cleared", CAN_WRITE, "Have NV settings been lost?  Write 0 to clear"},
  {"display_request", CAN_WRITE, "Should we initialize the display at boot?"},
  {"phase_enforcement", 0,
    "Board should have full security settings applied"},
  {"recovery_reason", 0, "Recovery mode reason for current boot"},
  {"recovery_request", CAN_WRITE, "Recovery mode request"},
  {"recovery_subcode", CAN_WRITE, "Recovery reason subcode"},
  {"recoverysw_boot", 0, "Recovery switch position at boot"},
  {"recoverysw_cur", 0, "Recovery switch current position"},
  {"recoverysw_ec_boot", 0, "Recovery switch position at EC boot"},
  {"ro_fwid", IS_STRING, "Read-only firmware ID"},
  {"tpm_attack", CAN_WRITE, "TPM was interrupted since this flag was cleared"},
  {"tpm_fwver", 0, "Firmware version stored in TPM", "0x%08x"},
  {"tpm_kernver", 0, "Kernel version stored in TPM", "0x%08x"},
  {"tpm_rebooted", 0, "TPM requesting repeated reboot"},
  {"tried_fwb", 0, "Tried firmware B before A this boot"},
  {"try_ro_sync", 0, "try read only software sync"},
  {"vdat_flags", 0, "Flags from VbSharedData", "0x%08x"},
  {"vdat_lfdebug", IS_STRING|NO_PRINT_ALL,
   "LoadFirmware() debug data (not in print-all)"},
  {"wipeout_request", CAN_WRITE, "Firmware requested factory reset (wipeout)"},
  {"wpsw_cur", 0, "Firmware write protect hardware switch current position"},
  /* Terminate with null name */
  {NULL, 0, NULL}
};

/* Longest Param name. */
static const int kNameWidth = 23;


/* Print help */
static void PrintHelp(const char *progname) {
  const Param *p;

  printf("Usage:\n"
         "  %s [--all]\n"
         "    Prints all parameters with descriptions and current values.\n"
         "    If --all is specified, prints even normally hidden fields.\n"
         "  %s [param1 [param2 [...]]]\n"
         "    Prints the current value(s) of the parameter(s).\n"
         "  %s [param1=value1] [param2=value2 [...]]]\n"
         "    Sets the parameter(s) to the specified value(s).\n"
         "  %s [param1?value1] [param2?value2 [...]]]\n"
         "    Checks if the parameter(s) all contain the specified value(s).\n"
         "    Stops at the first error.\n"
         "\n"
         "Valid parameters:\n", progname, progname, progname, progname);
  for (p = sys_param_list; p->name; p++) {
    printf("  %-*s  [%s/%s] %s\n", kNameWidth, p->name,
           (p->flags & CAN_WRITE) ? "RW" : "RO",
           (p->flags & IS_STRING) ? "str" : "int",
           p->desc);
  }
  printf("\n"
         "For more information, please see:\n"
         "https://chromium.googlesource.com/chromiumos/docs/+/HEAD/"
         "os_config.md#crossystem\n");
}


/* Find the parameter in the list.
 *
 * Returns the parameter, or NULL if no match. */
static const Param* FindParam(const char* name) {
  const Param* p;
  if (!name)
    return NULL;
  /* "legacy" term deprecated in favour of "altfw" (see: b/179458327) */
  if (!strcasecmp(name, "dev_boot_legacy")) {
    fprintf(stderr,
            "!!!\n"
            "!!! PLEASE USE 'dev_boot_altfw' INSTEAD OF 'dev_boot_legacy'\n"
            "!!!\n");
    name = "dev_boot_altfw";
  }
  for (p = sys_param_list; p->name; p++) {
    if (!strcasecmp(p->name, name))
      return p;
  }
  return NULL;
}

/* Return code of SetParam() below. */
enum {
  PARAM_SUCCESS = 0,
  PARAM_ERROR_UNKNOWN,
  PARAM_ERROR_READ_ONLY,
  PARAM_ERROR_INVALID_INT,
};

/* Set the specified parameter.
 *
 * Returns PARAM_SUCCESS if success, PARAM_ERROR_* if error. */
static int SetParam(const Param* p, const char* value) {
  if (!(p->flags & CAN_WRITE))
    return PARAM_ERROR_READ_ONLY;

  if (p->flags & IS_STRING) {
    return (0 == VbSetSystemPropertyString(p->name, value) ?
            0 : PARAM_ERROR_UNKNOWN);
  } else {
    char* e;
    int i = (int)strtol(value, &e, 0);
    if (!*value || (e && *e))
      return PARAM_ERROR_INVALID_INT;
    return (0 == VbSetSystemPropertyInt(p->name, i) ?
            0 : PARAM_ERROR_UNKNOWN);
  }
}

/* Compares the parameter with the expected value.
 *
 * Returns 0 if success (match), non-zero if error (mismatch). */
static int CheckParam(const Param* p, const char* expect) {
  if (p->flags & IS_STRING) {
    char buf[VB_MAX_STRING_PROPERTY];
  const int v = VbGetSystemPropertyString(p->name, buf, sizeof(buf));
  if (v != 0 || 0 != strcmp(buf, expect))
    return 1;
  } else {
    char* e;
    int i = (int)strtol(expect, &e, 0);
    int v = VbGetSystemPropertyInt(p->name);
    if (!*expect || (e && *e))
      return 1;
    if (v == -1 || i != v)
      return 1;
  }
  return 0;
}


/* Print the specified parameter.
 *
 * Returns 0 if success, non-zero if error. */
static int PrintParam(const Param* p) {
  if (p->flags & IS_STRING) {
    char buf[VB_MAX_STRING_PROPERTY];
  const int v = VbGetSystemPropertyString(p->name, buf, sizeof(buf));
  if (v != 0)
    return 1;
  printf("%s", buf);
  } else {
    int v = VbGetSystemPropertyInt(p->name);
    if (v == -1)
      return 1;
    printf(p->format ? p->format : "%d", v);
  }
  return 0;
}


/* Print all parameters with descriptions.  If force_all!=0, prints even
 * parameters that specify the NO_PRINT_ALL flag.
 *
 * Returns 0 if success, non-zero if error. */
static int PrintAllParams(int force_all) {
  const Param* p;
  int retval = 0;
  char buf[VB_MAX_STRING_PROPERTY];
  int result = 0;

  for (p = sys_param_list; p->name; p++) {
    if (force_all == 0 && (p->flags & NO_PRINT_ALL))
      continue;
    if (p->flags & IS_STRING) {
      result = VbGetSystemPropertyString(p->name, buf, sizeof(buf));
    } else {
      result = VbGetSystemPropertyInt(p->name);
      if (result != -1)
        snprintf(buf, sizeof(buf), p->format ? p->format : "%d", result);
      }
      printf("%-*s = %-30s # [%s/%s] %s\n", kNameWidth, p->name,
            ((result != -1) ? buf : "(error)"),
              (p->flags & CAN_WRITE) ? "RW" : "RO",
              (p->flags & IS_STRING) ? "str" : "int",
              p->desc);
  }
  return retval;
}


int main(int argc, char* argv[]) {
  int retval = 0;
  int i;

  char* progname = strrchr(argv[0], '/');
  if (progname)
    progname++;
  else
    progname = argv[0];

  /* If no args specified, print all params */
  if (argc == 1)
    return PrintAllParams(0);
  /* --all or -a prints all params including normally hidden ones */
  if (!strcasecmp(argv[1], "--all") || !strcmp(argv[1], "-a"))
    return PrintAllParams(1);

  /* Print help if needed */
  if (!strcasecmp(argv[1], "-h") || !strcmp(argv[1], "-?") ||
      !strcmp(argv[1], "--help")) {
    PrintHelp(progname);
    return 0;
  }

  /* Otherwise, loop through params and get/set them */
  for (i = 1; i < argc && retval == 0; i++) {
    char* has_set = strchr(argv[i], '=');
    char* has_expect = strchr(argv[i], '?');
    char* name = strtok(argv[i], "=?");
    const char* value = strtok(NULL, "=?");
    const Param* p;

    /* Make sure args are well-formed. '' or '=foo' or '?foo' not allowed. */
    if (!name || has_set == argv[i] || has_expect == argv[i]) {
      fprintf(stderr, "Poorly formed parameter\n");
      PrintHelp(progname);
      return 1;
    }
    if (!value)
      value=""; /* Allow setting/checking an empty string ('foo=' or 'foo?') */
    if (has_set && has_expect) {
      fprintf(stderr, "Use either = or ? in a parameter, but not both.\n");
      PrintHelp(progname);
      return 1;
    }

    /* Find the parameter */
    p = FindParam(name);
    if (!p) {
      fprintf(stderr, "Invalid parameter name: %s\n", name);
      PrintHelp(progname);
      return 1;
    }

    if (i > 1)
      printf(" ");  /* Output params space-delimited */
    if (has_set) {
      retval = SetParam(p, value);
      switch (retval) {
      case PARAM_SUCCESS:
        break;
      case PARAM_ERROR_READ_ONLY:
        fprintf(stderr, "Parameter %s is read-only\n", p->name);
        break;
      case PARAM_ERROR_INVALID_INT:
        fprintf(stderr, "Value %s is not a valid integer\n", value);
        break;
      default:
        fprintf(stderr, "Failed to set parameter %s\n", p->name);
        break;
      }
    } else if (has_expect)
      retval = CheckParam(p, value);
    else
      retval = PrintParam(p);
  }

  return retval;
}