Re: Booting a board with Redboot

[Gary Thomas <gary at mlbassoc dot com>]

Anders Brogestam wrote:
> Hi.
>
> I'm new to Redboot and are in the process of setting up a new board
> (with a MIPS) that will have Redboot and Linux. 
> I have managed to get a RAMROM version of RedBoot running on the board,
> and can use that with the serial consol (the board has no network
> connection).
> The questions that I have are:
>
> 1. One I have a Linux image on the board, how will Redboot automagically
> boot that image? All I can see is commands to do it using the CLI. 

Using 'fconfig', you can specify a script of commands to be executed
when RedBoot starts up.  These could include a way to load the Linux
kernel and then execute it.  This also leaves the possibility (via ^C)
to break into RedBoot for maintenance, etc.

> 2. The documentation for the "exec" command specifies that the option -b
> is used to specify the loaded address of the image (ie to me that
> indicates where the image is stored, in flash). The source though gives
> that -b is used as argument address... 
>
> 3. When a Linux image is booted, is it Redboot that copies the Linux
> image from flash to RAM or is it up to Linux?

Linux is usually started by loading it [from FLASH] into RAM
via a RedBoot command and then using the 'exec' command.  The "-b"
option would be used to tell 'exec' where the image is, although
with recent versions of RedBoot this can mostly be inferred from
the load operation.  For example,

  RedBoot> fi lo linux
  RedBoot> exec



--
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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