add bootcycle counter

Introduce 2 new commands.
`inccycle` to increase the bootcycle by one
`checkcycle` to check if bootcycle is reached. Returncode must be evaluated.

u-boot/common/Makefile

@@ -60,7 +60,7 @@ COBJS	= main.o circbuf.o \
 	  cmd_nand.o cmd_net.o cmd_nvedit.o \
 	  cmd_pci.o cmd_pcmcia.o cmd_portio.o \
 	  cmd_reginfo.o cmd_reiser.o cmd_scsi.o cmd_spi.o cmd_universe.o \
-	  cmd_usb.o cmd_vfd.o cmd_ethreg.o cmd_recovery.o \
+	  cmd_usb.o cmd_vfd.o cmd_ethreg.o cmd_recovery.o cmd_bootcycle.o \
 	  command.o console.o devices.o dlmalloc.o \
 	  environment.o env_common.o \
 	  env_nand.o env_dataflash.o env_flash.o env_eeprom.o \

u-boot/common/cmd_bootcycle.c

@@ -0,0 +1,114 @@
+/*
+ * (C) Copyright 2015
+ * Alexander Couzens, lynxis@fe80.eu
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <command.h>
+
+#ifdef CFG_CMD_BOOTCYCLE
+
+#ifndef MAX_REBOOTS
+#define MAX_REBOOTS 10
+#endif
+
+#define SRAM_BOOT_CYCLE 0xbd000100
+
+#define BOOT_CYCLE_MAGIC 0xfeedb00d
+#define BOOT_CYCLE_VERSION 1
+
+struct sram_boot_cycle
+{
+  uint32_t magic;
+  uint32_t version;
+  uint32_t counter;
+  uint32_t crc;
+};
+
+static int valid_boot_cycle(struct sram_boot_cycle *sram)
+{
+  if (sram->magic != BOOT_CYCLE_MAGIC)
+    return 0;
+
+  if (sram->version != BOOT_CYCLE_VERSION)
+    return 0;
+
+  uint32_t crc = crc32(0xdeadbeef, (void *)sram, sizeof(*sram) - 4);
+  if (crc != sram->crc)
+    return 0;
+
+  return 1;
+}
+
+static void init_boot_cycle(struct sram_boot_cycle *sram)
+{
+    sram->magic = BOOT_CYCLE_MAGIC;
+    sram->version = BOOT_CYCLE_VERSION;
+    sram->counter = 0;
+}
+
+void increase_boot_cycle(struct sram_boot_cycle *sram)
+{
+  if (!valid_boot_cycle(sram))
+    init_boot_cycle(sram);
+
+  sram->counter++;
+  sram->crc = (uint32_t) crc32(0xdeadbeef, (void *)sram, sizeof(*sram) - 4);
+}
+
+int do_inccycle(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) {
+  increase_boot_cycle((void *) SRAM_BOOT_CYCLE);
+	return CMD_RET_SUCCESS;
+}
+
+/* report failure when we need to go to rescue */
+int do_checkcycle(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+  struct sram_boot_cycle *sram = (void *) SRAM_BOOT_CYCLE;
+  /* when called we should ever have a valid boot cycle entry
+   * if it's invalid we have most likely a broken bootloader or hw? */
+  if (!valid_boot_cycle(sram)) {
+    printf("Invalid boot cycle partition!\n");
+    return CMD_RET_FAILURE;
+  }
+  printf("bootcycle counter: %d\n", sram->counter);
+
+  if (sram->counter >= threshold) {
+    printf("Reached maximum reboot.\n");
+    return CMD_RET_FAILURE;
+  }
+
+	return CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(
+	checkcycle,	1,	0,	do_checkcycle,
+	"checkcycle - check if we need to boot rescue system\n",
+	NULL
+);
+
+U_BOOT_CMD(
+	inccycle,	1,	0,	do_inccycle,
+	"inccycle - increase boot cycle counter\n",
+	NULL
+);
+
+#endif	/* CFG_CMD_BOOTCYCLE */

u-boot/include/configs/carambola2.h

@@ -11,6 +11,8 @@
 /* enable watchdog */
 #define CONFIG_HW_WATCHDOG
 
+#define CFG_CMD_BOOTCYCLE
+
 /*-----------------------------------------------------------------------
  * FLASH and environment organization
  *-----------------------------------------------------------------------

u-boot/include/configs/skylab.h

@@ -11,6 +11,8 @@
 /* enable watchdog */
 #define CONFIG_HW_WATCHDOG
 
+#define CFG_CMD_BOOTCYCLE
+
 /*-----------------------------------------------------------------------
  * FLASH and environment organization
  *-----------------------------------------------------------------------