On 03/14/2012 03:16 AM, Mike Frysinger wrote:
On Tuesday 13 March 2012 17:31:02 Falauto, Gerlando wrote:
From: Mike Frysinger [mailto:vapier@gentoo.org]
On Tuesday 13 March 2012 16:17:52 Jason Cooper wrote:
On Tue, Mar 13, 2012 at 04:11:29PM -0400, Mike Frysinger wrote:
On Tuesday 13 March 2012 14:25:07 Gerlando Falauto wrote:
- an out-of-boundary-check againts the flash size so at least a
warning is issued when you use too big a size value
i'm not sure about this. if you want to do size checking, then enable the hush shell and do it in a script.
Is there a programatic way to get the size of the flash at runtime from the hush script?
no. question is, do you really need that ? sounds like you know ahead of time how big the space is for u-boot, so the size of the flash doesn't matter.
Can't the same command also be used for burning something *other than* u-boot (e.g. a kernel, config section, or something like that)? So the size of the flash *does matter*, doesn't it?
you have to show how it actually does matter. when you deploy a board and programming the flash directly, you don't let the regions grow arbitrarily. you know how big the space for u-boot, or the kernel, or dedicated config space, or anything else is going to be. if you want to arbitrarily append things, then you're going to use a filesystem. -mike
You're right, but I failed to stress enough one point. The thing is, if you issue e write (or erase) and accidentally cross the flash size boundary, you get a wraparound (or aliasing, or whatever you want to call it) so that you end up overwriting (e.g. zeroing out bits) the initial sectors of the flash. Which is where u-boot normally lies. [At least, that's the way I understand things are working right now.] I hope you'd agree that this is *a bad thing (TM)*. My concern is not about the fully aware u-boot developer, who normally has some other way to restore a dead board (JTAG, rom monitor, etc...). My conncern is about mistakes made by the absent-minded user who reads an upgrade procedure somewhere, puts an extra zero, and ends up bricking their board, whereas it could have been easily avoided.
Thanks, Gerlando