I installed flash module (4MB) to Cisco877, then formatted the flash and uploaded IOS version 12.4(11)XJ into the router. After turned off the router more than 1 day, it could not open the boot file. The size of IOS is 0 byte when I typed the command 'dir flash:' in rommon mode. The information below is the error message I got when boot the router.
flashfs: Checking block 151...bad block number (407)
flashfs: erasing block 151...done.
flashfs: Checking block 152...bad checksum (58096 != 53697)
flashfs: erasing block 152...done.
flashfs: erasing block 152 with status unknown[0xe]
flashfs: inconsistent sector list, fileid 2, parent_fileid 0
flashfs: block 151 not available or in use, state: unknown[0xe].
flash: file system initialization failed
Could not open boot directory: flash:/
Unable to open boot file
Could anyone suggest me what I should do?