Add crossystem support for nvram_cleared and kern_nv

firmware/lib/vboot_nvstorage.c

 /* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* Non-volatile storage routines.
  */
 
 #include "utility.h"
 #include "vboot_common.h"
 #include "vboot_nvstorage.h"
 
 /* Constants for NV storage.  We use this rather than structs and
  * bitfields so the data format is consistent across platforms and
  * compilers. */
 #define HEADER_OFFSET                0
 #define HEADER_MASK                     0xC0
 #define HEADER_SIGNATURE                0x40
 #define HEADER_FIRMWARE_SETTINGS_RESET  0x20
 #define HEADER_KERNEL_SETTINGS_RESET    0x10
 
 #define BOOT_OFFSET                  1
 #define BOOT_DEBUG_RESET_MODE           0x80
-#define BOOT_TRY_B_COUNT                0x0F
+#define BOOT_TRY_B_COUNT_MASK           0x0F
 
 #define RECOVERY_OFFSET              2
 #define LOCALIZATION_OFFSET          3
 
 #define FIRMWARE_FLAGS_OFFSET        5
 #define FIRMWARE_TRIED_FIRMWARE_B       0x80
 #define FIRMWARE_FW_VERIFIED_KERNEL_KEY 0x40
 
 #define KERNEL_FIELD_OFFSET         11
 #define CRC_OFFSET                  15
@@ skipping 65 matching lines @@
 
     case VBNV_KERNEL_SETTINGS_RESET:
       *dest = (raw[HEADER_OFFSET] & HEADER_KERNEL_SETTINGS_RESET ? 1 : 0);
       return 0;
 
     case VBNV_DEBUG_RESET_MODE:
       *dest = (raw[BOOT_OFFSET] & BOOT_DEBUG_RESET_MODE ? 1 : 0);
       return 0;
 
     case VBNV_TRY_B_COUNT:
-      *dest = raw[BOOT_OFFSET] & BOOT_TRY_B_COUNT;
+      *dest = raw[BOOT_OFFSET] & BOOT_TRY_B_COUNT_MASK;
       return 0;
 
     case VBNV_RECOVERY_REQUEST:
       *dest = raw[RECOVERY_OFFSET];
       return 0;
 
     case VBNV_LOCALIZATION_INDEX:
       *dest = raw[LOCALIZATION_OFFSET];
       return 0;
 
@@ skipping 44 matching lines @@
 
     case VBNV_DEBUG_RESET_MODE:
       if (value)
         raw[BOOT_OFFSET] |= BOOT_DEBUG_RESET_MODE;
       else
         raw[BOOT_OFFSET] &= ~BOOT_DEBUG_RESET_MODE;
       break;
 
     case VBNV_TRY_B_COUNT:
       /* Clip to valid range. */
-      if (value > BOOT_TRY_B_COUNT)
-        value = BOOT_TRY_B_COUNT - 1;
+      if (value > BOOT_TRY_B_COUNT_MASK)
+        value = BOOT_TRY_B_COUNT_MASK;
 
-      raw[BOOT_OFFSET] &= ~BOOT_TRY_B_COUNT;
+      raw[BOOT_OFFSET] &= ~BOOT_TRY_B_COUNT_MASK;
       raw[BOOT_OFFSET] |= (uint8_t)value;
       break;
 
     case VBNV_RECOVERY_REQUEST:
       /* Map values outside the valid range to the legacy reason, since we
        * can't determine if we're called from kernel or user mode. */
       if (value > 0xFF)
         value = VBNV_RECOVERY_LEGACY;
       raw[RECOVERY_OFFSET] = (uint8_t)value;
       break;
@@ skipping 27 matching lines @@
       break;
 
     default:
       return 1;
   }
 
   /* Need to regenerate CRC, since the value changed. */
   context->regenerate_crc = 1;
   return 0;
 }