[U-Boot] [PATCH 5/5] Allow tftp server to be different from bootp/dhcp server

[Simon Glass]

On Tue, Apr 12, 2011 at 2:56 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
> In message <1302642840-6958-5-git-send-email-sjg at chromium.org> you wrote:
>> In many environments the DHCP server (which provides IP addresses) is not
>> under control of the individual engineer. While it is required in order to
>> connect to the corporate network, it doesn't provide useful information for
>> booting. For example, it may be set up for PC imaging and provide a bootfile
>> and tftp server for pxelinux.
>>
>> To deal with this, this commit provides for a separate tftpserverip environment
>> variable. If this is defined, then this IP address is used in preference
>> to serverip. A new CONFIG_BOOTP_IGNORE_BOOTFILE option is provided to indicate
>> that any bootfile name returned by the DHCP server is bogus and should be
>> ignored.
>
> Why don't you simply re-assing another value to "serverip" before
> doing any TFTP transfers?

The point here is to initialize the ethernet only once.

setenv autoload n; bootp; tftp...

does two initializations which costs a few seconds (to get a link, etc.).

We want to just do this:

setenv bootfile "uImage"; setenv autoload y; bootp

The reason we can't use bootp to load the kernel in this situation is
that the DHCP server is not under our control. This is a common
situation at larger companies.

>
> This can be done with trivial scripting, without any code changes.
>
>> To use this feature, just setenv tftpserverip to the address of your TFTP
>> server and define CONFIG_BOOTP_IGNORE_BOOTFILE in your board file.
>
> Why don't you simply set the "autoload" environment variable to "no"?
> This is the documented way to do exactly this.
>
> Sorry, but I see no use for this patch.

Please take another look.

Regards,
Simon

>
> NAK.
>
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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>                                 - Terry Pratchett, _Guards! Guards!_
>