Confused by the term "Rom Monitor", "RXBOOT", "Bootstrap"

Confused by the term "Rom Monitor", "RXBOOT", "Bootstrap"

Post by Wayn » Mon, 05 Oct 1998 04:00:00



Hi all,

I read the above terms in the Cisco CD and get confused by them.

I send a break signal to the router during the first 60 seconds of reloading
to get this ">" prompt. I can also get this ">" prompt by changing the
config-register to 0x2100.

I tried to change the config-register to 0x2101 and it gives me the
"Router(boot)" prompt.

How do people usually call these modes?

Actually, which is the rom monitor mode? Which is the RXBOOT? Which is the
Bootstrap? Pls advise.

I am a newbie to Cisco and please forgive my simple question.

Thanks very much!

Wayne

 
 
 

Confused by the term "Rom Monitor", "RXBOOT", "Bootstrap"

Post by Terry Kenned » Mon, 05 Oct 1998 04:00:00



> I read the above terms in the Cisco CD and get confused by them.

  Different Cisco router models have different types of implementation with
slightly different ways of accessing and updating them. More below.

Quote:> I send a break signal to the router during the first 60 seconds of reloading
> to get this ">" prompt. I can also get this ">" prompt by changing the
> config-register to 0x2100.

  This is the ROM Monitor (ROMMON). Some Cisco routers (75xx, 4700M, etc.)
have this as a separate ROM (or set of ROMs) while others (25xx) integrate
it into the boot image. It's used for low-level stuff like password recovery
and also sets up the hardware to a known state before calling the boot image.

Quote:> I tried to change the config-register to 0x2101 and it gives me the
> "Router(boot)" prompt.

  This is the router's boot image, often called the RXBOOT. As mentioned
above, on the 25xx it's integrated onto the same set of ROM chips as the
ROMMON. On the 75xx and 4700M it's on a separate flash module called the
bootflash.

  If you are netbooting a router, you need this image to download the main
IOS image, since the ROMMON doesn't have any IP capability. If you aren't
netbooting, it's usually just a waste of time and may cause Frame Relay or
BGP flapping as it brings up all the interfaces before it transfers con-
trol to the regular IOS image in flash. If you have lots of interfaces de-
fined, it's a real time-waster. Cisco's TAC told me "most ISP's just delete
it". We did. Note that if you delete the bootflash image and don't have a
valid image in main flash (or a way to put one there, like on another PCMCIA
card on a 75xx) you're stuck, so deleting it should be carefully considered
first.

  Once all the booting is done, you're running the regular IOS stored on the
regular flash memory. Depending on the router model, it may either run from
flash, copy to RAM and run, or uncompress to RAM and run.

  Further, different routers support different levels of flash filesystems.
On the lower-end routers flash can hold one file, and putting a new one in
involves erasing the existing one. These routers support partitioning the
flash SIMM(s) into 2 partitions so that two files can be stored. The high-
end systems (like the 75xx) can store multiple files on flash, and can in-
dividually delete files without erasing the whole flash module.

        Terry Kennedy             Operations Manager, Academic Computing

        +1 201 915 9381 (voice)   +1 201 435-3662 (FAX)

 
 
 

Confused by the term "Rom Monitor", "RXBOOT", "Bootstrap"

Post by Barton F. Bru » Tue, 06 Oct 1998 04:00:00


...

Quote:>   Further, different routers support different levels of flash filesystems.
> On the lower-end routers flash can hold one file, and putting a new one in
> involves erasing the existing one. These routers support partitioning the
> flash SIMM(s) into 2 partitions so that two files can be stored. The high-
> end systems (like the 75xx) can store multiple files on flash, and can in-
> dividually delete files without erasing the whole flash module.

The 25xx can take as many files in each partition as you can fit,
but you need to explicitly reference the file if you want to boot it.

        boot system flash 2:pr12016

would boot that image even if it is not the first in the 2nd partition.

To get the 2nd and beyond image into FLASH, simply say "No" to the request to
erase flash.

You can put anything in there and TFTP serve it, too. Need not be the
typically expected 25xx binary or config file.

Lacking the file system of the larger routers, there is no delete
and squeeze capability, so, yes, when you need to clean up you erase them all
together.

 
 
 

Confused by the term "Rom Monitor", "RXBOOT", "Bootstrap"

Post by Wayne Cha » Tue, 06 Oct 1998 04:00:00


Hi Barton,

Thanks for your information.

I have a 3204 with the following flash config.

        3204>sh flash all

        System flash directory:
        File  Length   Name/status
                addr      fcksum  ccksum
          1   3180172  2500-ip-10.3-12
                0x40      0xF36D  0xF36D
        [3180236 bytes used, 5208372 available, 8388608 total]
        8192K bytes of processor board System flash (Read ONLY)

           Chip    Bank    Code      Size      Name
            1      1       89A2      1024KB    INTEL 28F008SA
            2      1       89A2      1024KB    INTEL 28F008SA
            3      1       89A2      1024KB    INTEL 28F008SA
            4      1       89A2      1024KB    INTEL 28F008SA
            1      2       89A2      1024KB    INTEL 28F008SA
            2      2       89A2      1024KB    INTEL 28F008SA
            3      2       89A2      1024KB    INTEL 28F008SA
            4      2       89A2      1024KB    INTEL 28F008SA
        Executing current image from System flash

I beleive that I have 2 4MB flash partitions. When I tried to download
another IOS image to the flash, it requested me to get into the RXBOOT
mode. How can I download the image in EXEC mode? Do I need the feature -
Flash Load Helper (FLH)? I read FLH in the Cisco CD. What is the oldest
version of ROM that support FLH?

Lastly, if I finally have 2 IOS images in the flash. Is it possible to
erase ONLY one of them? The command "ERASE FLASH" does not give me any
option on specifying the flash space.

Thanks in advance.

Wayne



> ...
> >   Further, different routers support different levels of flash filesystems.
> > On the lower-end routers flash can hold one file, and putting a new one in
> > involves erasing the existing one. These routers support partitioning the
> > flash SIMM(s) into 2 partitions so that two files can be stored. The high-
> > end systems (like the 75xx) can store multiple files on flash, and can in-
> > dividually delete files without erasing the whole flash module.

> The 25xx can take as many files in each partition as you can fit,
> but you need to explicitly reference the file if you want to boot it.

>         boot system flash 2:pr12016

> would boot that image even if it is not the first in the 2nd partition.

> To get the 2nd and beyond image into FLASH, simply say "No" to the request to
> erase flash.

> You can put anything in there and TFTP serve it, too. Need not be the
> typically expected 25xx binary or config file.

> Lacking the file system of the larger routers, there is no delete
> and squeeze capability, so, yes, when you need to clean up you erase them all
> together.

 
 
 

Confused by the term "Rom Monitor", "RXBOOT", "Bootstrap"

Post by Barton F. Bru » Wed, 07 Oct 1998 04:00:00



> Hi Barton,

> Thanks for your information.

> I have a 3204 with the following flash config.

>    3204>sh flash all

>    System flash directory:
>    File  Length   Name/status
>            addr      fcksum  ccksum
>      1   3180172  2500-ip-10.3-12
>            0x40      0xF36D  0xF36D
>    [3180236 bytes used, 5208372 available, 8388608 total]
>    8192K bytes of processor board System flash (Read ONLY)

>       Chip    Bank    Code      Size      Name
>        1      1       89A2      1024KB    INTEL 28F008SA
>        2      1       89A2      1024KB    INTEL 28F008SA
>        3      1       89A2      1024KB    INTEL 28F008SA
>        4      1       89A2      1024KB    INTEL 28F008SA
>        1      2       89A2      1024KB    INTEL 28F008SA
>        2      2       89A2      1024KB    INTEL 28F008SA
>        3      2       89A2      1024KB    INTEL 28F008SA
>        4      2       89A2      1024KB    INTEL 28F008SA
>    Executing current image from System flash

> I beleive that I have 2 4MB flash partitions. When I tried to download
> another IOS image to the flash, it requested me to get into the RXBOOT
> mode. How can I download the image in EXEC mode? Do I need the feature -
> Flash Load Helper (FLH)? I read FLH in the Cisco CD. What is the oldest
> version of ROM that support FLH?

> Lastly, if I finally have 2 IOS images in the flash. Is it possible to
> erase ONLY one of them? The command "ERASE FLASH" does not give me any
> option on specifying the flash space.

The 3204 takes some very expensive EPROMS to upgrade to take the latest
boot code. I hapen to have a 3204 running much much newer code than
cisco would expect to see in there, and had to move the little push-on
jumper near to boot proms over to the larger setting. I at least
have FLH and other goodies.

I expect you are running relatively oldish boot code, and am not sure
what yours supports. SHO VER will at least tell you what # you have.

As a minimum I would try partitioning that into 2 banks for Dual
Flash Bank use.

        partition flash 2 4 4

and at that point you should have 2 seperate 4 meg banks.

Try compressing a recent ip image that is over 4 meg to less than
the size of the 2nd bank. on a friendly local unix machine the
compress utility will make you a <whatever>.Z file.

Now:

        copy tftp flash

and use partition 2

then setup:

        boot system flash 2:
        boot system flash 1:

with 16 meg of DRAM (4x36 70ns PARITY) already in and known to
run in your previous config, see if you come up.

I bet you will boot the new image into dram, decompress it, and
when you do a SHO FLASH, both partitions should be (read/write)!

If you have more than one image in a partition, you must specify
which you want:

        boot system flash 1:2500-ip-10.3-12

I do not remember if the 10.3 (gads that is old...) was -l relocatable
style or not.

In general your 3204 is just a 2503 without all the VLSI. It however WAS
listed by cisco as both a run from DRAM and a run from FLASH machine,
so this boot scheme info is quite normal for this chassis. cisco just
does not want you to know it applies to 25xx routers too.