灌IOS的问题分析

问题：
    一台3620的路由器，启动只能到rommon>。看了一下flash里面没有ios。就用xmodem传了一个ios进去。能正常启动了。可是 show flash 里面还是看不见ios的文件。而且只要断电就又回到rommon>，什么原因啊。

rommon 1 >
rommon 1 > dir flash:
        File size           Checksum   File name
     2742 bytes (0xab6)      0xb94d    stat
rommon 2 > xmodem -r
Do not start the sending program yet...

Invoke this application only for disaster recovery.
Do you wish to continue? y/n  [n]:  y
Ready to receive file  ...

Download Complete!
program load complete, entry point: 0x80008000, size: 0x58e9d4
Self decompressing the image : #################################################
################################################################################
################################################################################
################################################################################
################################################################################
################################################################################
################################################# [OK]

Smart Init is enabled
smart init is sizing iomem
 ID            MEMORY_REQ                 TYPE
000037          0X00056400 Combination Single Ethernet 2 WAN
               0X0010A6F8 public buffer pools
               0X00211000 public particle pools
TOTAL:          0X00371AF8

If any of the above Memory Requirements are
"UNKNOWN", you may be using an unsupported
configuration or there is a software problem and
system operation may be compromised.
Rounded IOMEM up to: 4Mb.
Using 6 percent iomem. [4Mb/64Mb]

正常进入以后看flash
aaa#show flash

System flash directory:
File  Length   Name/status
 1   2742     stat
[2808 bytes used, 16774408 available, 16777216 total]
16384K bytes of processor board System flash (Read/Write)

分析：
    首先可以看看寄存器，我们会发现没有寄存器值，同时也没有boot flash:x.bin之类的，flash里面是空的。是无法boot的。
    其次xmodem -r是传到mem里去了，restart后就没有了。restart前可以通过copy tftp flash再传一个，就可以解决问题了。