Greetings,
On Wed, 29 Aug 2007, Peter Stuge wrote:
On Wed, Aug 29, 2007 at 03:58:56PM +0200, Stefan Reinauer wrote:
- one requirement would be: if payload can not be loaded, attempt
to load it via serial or usb console via ymodem protocol.
Only ymodem with serial - USB is already a reliable transport.
On Wed, Aug 29, 2007 at 04:38:47PM +0200, Carl-Daniel Hailfinger wrote:
Agreed. That way, we could even abuse a fallback image for early porting without the need to reflash continuously.
Yes - this has been a thought of mine all the way since the Symposium.
I've been thinking about that a good bit lately. Once the serial port and CAR is up, a very simple monitor program should be able to accept simple commands and programs from the serial console.
Beyond development, a small, simple and stripped down fallback that can either jump to the normal image or bring up the monitor would be a lot more likely to fit in a boot block and leave room for the normal image to have a good sized payload.
The other thought is having a real boot block that isn't erased when either the normal image or the payload are updated. Even if the image is perfect, a power failure (or someone tripping over a power cord) at the wrong time can ruin your day if the box is production rather than development (and so isn't fitted with a BIOS saviour, LPC hack or even a socketed flash). In the few commercial deployments I did, I had LinuxBIOS set the lockdown bits (intel flash) on the sectors for the fallback image so the customer could have a blessed payload update procedure that wouldn't leave them with a brick.
G'day, sjames
//Peter
-- linuxbios mailing list linuxbios@linuxbios.org http://www.linuxbios.org/mailman/listinfo/linuxbios
||||| |||| ||||||||||||| ||| by Linux Labs International, Inc. Steven James, CTO
55 Marietta Street Suite 1830 Atlanta, Ga 30303 866 824 9737 support