[jornada] 720 randomness

Hi All;

I was recently lucky enough to receive a 720 with the magic flash
board. The flash already had familiar 0.5 installed ( blast from the
past ;-) ), I got to work upgrading the bootloader ( to 2.19.28 ) and
kernel ( 2.4.19-rmk6-pxa1-hh3-j720 ) to get the suspend etc working.

Some issues I accounted, that I'll note for list archives.

  - The kernel seems only to work if built with a 2.92 toolchain.
    It hangs at inialising the fb, compiling with anything later.
    This is very odd.

  - The bootloader was setting /dev/mtdblock/1 whilst the kernel was
    expecting /dev/mtdblock1 . SEtting the bootloader params to this
    fixed it.
 
  - The audio stuff in hh.org cvs kernel src is broken ( I think ALSA
    is prefered now for th ipaqs - anyone tried that on 720 ? ).
    Im yet to retry a CVS kernel after figuring out above 2 problems.

Id like to try a more recent familiar image, but I've read in archives
theres problems with busybox and 'low entry points?' - has anyone
encountered/worked round this ?

Noticing the kernel was missing /dev/apm and also exporting frontlight
control to userspace I decided to tinker around a little ( it should
be noted Im *no* kernel expert ).

I hacked a simple /proc entry to list basic info about the frontlight
and battery via the mcu calls.

Thats when I noticed a little problem with the functions that use the
mcu stuff, there seems to been no 'locking' in place so if 2
'things' speak to the mcu at once there messages interfere and bad
stuff can happen. Has anyone looked at this ? is it just a case of
wrapping an mcu based calls with spinlocks ? or is a more complex
solution required ? If this could be fixed, it'd be pretty trivial to
add frontlight control from userspace.

The kernel source has a func to read the 3 bytes of data about battery
source(s) attached. It should be pretty easy to plug this into
/dev/apm if someone knows what the bits in these bytes mean.
http://lorien.handhelds.org/ftp.handhelds.org/linux/hp/720/jornada720.txt
gives info on how to get the bytes but no more :/

Finally some nice shots of 720 once Id updated the software a little;
http://handhelds.org/~mallum/j720/

Many thanks;

  -- Matthew Allum
     http://handhelds.org/~mallum
Received on Thu Jul 17 2003 - 20:17:24 EDT