今天遇到了一個很奇怪的事情，上電後，isr4400無法載入image，查看了一下bootflash，發現又是好的，image也是存在的而且size也是完好無損，斷電、reset都試過了，每次都是直接進入rommon。

1. 檢車bootflash檔案系統是否完好。 結果是好的

rommon 4 > dir bootflash: 
File System: EXT2/EXT3

11         16384     drwx------     lost+found
811201     4096      drwxrwxrwx     .prst_sync
12         89328     -rw-r--r--     bgp-pns-ovld1.config
14         1752      -rw-r--r--     bgp-pns-ovld1.clean
827425     4096      drwxrwxrwx     .installer
227137     4096      drwxr-xr-x     core
64897      4096      drwxr-xr-x     .rollback_timer
13         0         -rw-------     tracelogs.874
648961     229376    drwxrwxrwx     tracelogs
18         2151      -rw-r--r--     crdc-config
730081     4096      drwxrwx---     vman_fdb
21         98207     -rw-r--r--     test
275809     4096      drwxr-xr-x     quit
 

2. unset BOOT, 讓路由器自己去選擇image

<strong>rommon 1 > unset BOOT</strong>
rommon 2 > set
PS1=rommon ! > 
MCP_STARTUP_TRACEFLAGS=00000000:00000000
RET_2_RTS=
EULA_ACCEPTED=TRUE
CRASHINFO=crashinfo_FAILED
TFTP_FILE=bzImage.SSA.bin
IP_ADDRESS=10.75.167.164
IP_SUBNET_MASK=255.255.255.0
DEFAULT_GATEWAY=10.75.167.1
TFTP_SERVER=10.74.9.48
THRPUT=2000000
LICENSE_BOOT_LEVEL=appxk9,appxk9:esg;uck9,uck9:esg;securityk9,securityk9:esg;
BSI=0
RANDOM_NUM=958801295
RET_2_RCALTS=1406805522
?=0
rommon 3 > sync
rommon 4 > reset


Resetting .......








Initializing Hardware ...


System integrity status: 00000610
Rom image verified correctly




System Bootstrap, Version 12.2(20130621:100325) [dgreeson-15_3_3R_S 101], DEVELOPMENT SOFTWARE
Copyright (c) 1994-2013  by cisco Systems, Inc.
Compiled Fri 06/21/2013  6:12:33.26 by dgreeson


Current image running: Boot ROM0


Last reset cause: PowerCycleRequest
Cisco ISR4451/K9 platform with 4194304 Kbytes of main memory


rommon 1 > set
 

原因就是，硬體工程師除錯板卡的時候，把config register更改了，直接進入rommon，啟動diag。

比較有意思的是，不能直接把confreg更改成2102，而必須是先更改成2142，然後更改成2102.

Resetting .......




Initializing Hardware ...

System integrity status: 00000610
Rom image verified correctly


System Bootstrap, Version 12.2(20130621:100325) [dgreeson-15_3_3R_S 101], DEVELOPMENT SOFTWARE
Copyright (c) 1994-2013  by cisco Systems, Inc.
Compiled Fri 06/21/2013  6:12:33.26 by dgreeson

Current image running: Boot ROM0

Last reset cause: PowerCycleRequest
Cisco ISR4451/K9 platform with 4194304 Kbytes of main memory

rommon 1 > set
PS1=rommon ! > 
MCP_STARTUP_TRACEFLAGS=00000000:00000000
RET_2_RTS=
EULA_ACCEPTED=TRUE
CRASHINFO=crashinfo_FAILED
TFTP_FILE=bzImage.SSA.bin
IP_ADDRESS=10.75.167.164
IP_SUBNET_MASK=255.255.255.0
DEFAULT_GATEWAY=10.75.167.1
TFTP_SERVER=10.74.9.48
THRPUT=2000000
LICENSE_BOOT_LEVEL=appxk9,appxk9:esg;uck9,uck9:esg;securityk9,securityk9:esg;
BSI=0
RANDOM_NUM=958801295
RET_2_RCALTS=1406805522
?=0
confreg=0X2102
rommon 2 > ?
alias               set and display aliases command
boot                boot up an external process
break               set/show/clear the breakpoint
confreg             configuration register utility
context             display the context of a loaded image
cookie              display contents of cookie PROM in hex
dev                 list the device table
dir                 list files in file system
dis                 display instruction stream
frame               print out a selected stack frame
help                monitor builtin command help
history             monitor command history
meminfo             main memory information
repeat              repeat a monitor command
reset               system reset
set                 display the monitor variables
showmon             display currently selected ROM monitor
stack               produce a stack trace
sync                write monitor environment to NVRAM
sysret              print out info from last system return
token               display board's unique token identifier
tsec                print out info from the ethernet driver
unalias             unset an alias
unset               unset a monitor variable
rommon 3 > confreg 0x2102


monitor: command "confreg 0x2102" not found


rommon 4 > 
                  " not found
monitor: command "

rommon 5 > confreg 0x2142


You must reset or power cycle for new config to take effect
rommon 6 > reset

Resetting .......




Initializing Hardware ...

System integrity status: 00000610
Rom image verified correctly


System Bootstrap, Version 12.2(20130621:100325) [dgreeson-15_3_3R_S 101], DEVELOPMENT SOFTWARE
Copyright (c) 1994-2013  by cisco Systems, Inc.
Compiled Fri 06/21/2013  6:12:33.26 by dgreeson

Current image running: Boot ROM0

Last reset cause: PowerCycleRequest
Cisco ISR4451/K9 platform with 4194304 Kbytes of main memory


no valid BOOT image found
Final autoboot attempt from default boot device...
File size is 0x00015cf0
Located bgp-pns-ovld1.config 
Image size 89328 inode num 12, bks cnt 22 blk size 8*512