[U-Boot-Users] outline of bootm script

Wolfgang Denk wd at denx.de
Wed Aug 6 22:21:51 CEST 2008


In message <489A01A3.6000800 at ge.com> you wrote:
>
> > bootm restore (undo anything prep did, reset state tracking)
> 
> Ooo, that sounds hard.  If we are only re-enabling interrupts/usb/caches 
> it probably is manageable, but my hackles.

ACK. And if we really restore anything, than just interrupts and
caches, but not any interfaces.

> > We could also have some "bootm query <foo>" to expose the internal  
> > state if that's useful.  We could completely get rid of the various  
> > "env" vars that impact bootm and just make them state variables  
> > ("verify", "autostart", "bootm_size", "bootm_low", ...)
> 
> State is bad.

ACK.

> Aside: verify should be an image verify command, not a env variable flag 
> (see below).  This is probably true of most of the current env 

We alreay have a verify command. It's called "imls".

> variables: the reason we need them is because we kept throwing stuff 
> into "bootm" and then controlling it with env variables rather than 
> having a sequence and controlling it with what commands are in the 
> sequence.  (Part of my simplification argument...)

Hint: keep it backwards compatible, please.

> I also was thinking we should invent a new major/minor command as you 
> outlined, but it didn't occur to me that "bootm" would be a good major 
> command.  This is a good idea: a bare "bootm <addr> (<addr>|-) <addr>" 
> could be used for backward compatibility and "bootm <subcmd>" for New 
> Improved[tm] functionality.

How do your differentiate beween <addr> and <subcmd> then?

> Having said that, I was thinking and would advocate pushing 
> functionality out of bootm and into other commands, as appropriate.  As 
> an example, bootm doesn't need to do *any* fdt stuff, the "fdt" built-in 
> has all the capability we need (or should).  The same may be also true 
> about load_os and load_initrd - they are copy-with-(optional)-
> decompression operations (we may need additional commands for these).

ACK.

> Philosophy: bootm should do only bootm stuff.  It (probably) should not 
> do any image stuff (find/copy/decompress/verify).  It (probably) should 
> not do any fdt stuff (board fixup, other?).  Etc...

ACK.

Best regards,

Wolfgang Denk

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