Small size of diskboot.bin as a cause of unstable booting

alvm

Small size of diskboot.bin as a cause of unstable booting

« on: 25 / April / 2012, 05:47:19 »

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Hi,

I try to boot diskboot.bin which has 11 kB size. boot() isn't called for 6-7 attempts of 10.

UART out for successful attempts:

Code: [Select]

[00]#[00]
Startdiskboot.bin
[00]

Start program on RAM

boot()    <------------------------- CHDK boot()

Event[1]>

.....

[00] <------------ poweroff key pressed

UART out for unsuccessful attempts:

Code: [Select]

[00]#[00]
Startdiskboot.bin
[00]

Start program on RAM

.....  <------------ cam hangs or wait anything

[00] <------------ battary cover is open (hard poweroff)

How size of diskboot.bin can influence to booting process?

Thanks,
Alex.

« Last Edit: 25 / April / 2012, 07:43:11 by alvm »

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cppasm

Re: Small size of diskboot.bin as a cause of unstable booting

« Reply #1 on: 25 / April / 2012, 07:16:07 »

It's a known behavior, but exact reasons is not clear.
This may be due to caches not flushed to memory for small file, or that firmware just checks for some mark in memory to be overwritten by diskboot.bin file's data, and if not - just hang (small file intentionally interpreted as invalid).
For stable booting you should pad diskboot.bin to something like 20KB with any data.

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alvm

Re: Small size of diskboot.bin as a cause of unstable booting

« Reply #2 on: 25 / April / 2012, 07:38:04 »

Quote from: cppasm on 25 / April / 2012, 07:16:07

For stable booting you should pad diskboot.bin to something like 20KB with any data.

I've tried boot diskboot with 35 kB size. 1 - 2 unsuccesful attepts from 100.

Quote from: cppasm on 25 / April / 2012, 07:16:07

This may be due to caches not flushed to memory for small file, or that firmware just checks for some mark in memory to be overwritten by diskboot.bin file's data, and if not - just hang (small file intentionally interpreted as invalid).

In this case not booting always, rigth? And cam doesn't hang - see [00] console in UART out. As I suppose cam waits anything actions.

« Last Edit: 25 / April / 2012, 07:42:10 by alvm »

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