Re: [9fans] Suggestion: Programming Tutorial for /sys/doc

[erik quanstrom <quanstro@quanstro.net>]

> The Nov 3rd image didn't work for me.  But, by turning off extended IDE mode
> for my HDD, I was able to get an error message in assembly rather than it
> just hanging without any error message.  (Not sure if that makes it
> irrelevant, but anyway.)
> 
> http://home.earthlink.net/~eldanen/pastes/dmesg
> http://home.earthlink.net/~eldanen/pastes/plan9output
> 
> The following was appended to "plan9output":
> 
> FLAGS=10246 TRAP=0 ENCODE=0 PC=80030089
> AX 00000000 BX 8004483c CX 00000000 DX 00000000
> SI 0000020 DI 00000000 BP 80047e6c
> CS 0010 DS 0008 ES 0008 FS 0008 GS 0008
> CRO 80000011 CR2 00f0c05c CR3 0000c000
> panic: exception/interrupt 0
> 
> Press almost any key to reset...

it didn't print anything else, did it?  the pc indicates that these
lines should have been executed

; acid /n/sources/plan9/386/9loaddebug
/n/sources/plan9/386/9loaddebug:386 plan 9 boot image
/sys/lib/acid/port
/sys/lib/acid/386
acid: src(0x80030089)
/sys/src/boot/pc/ether.c:119

/n/sources/plan9/sys/src/boot/pc/ether.c
108 			print("ether#%d: %s: port 0x%luX irq %lud",
109 				ctlr->ctlrno, ctlr->type, ctlr->port, ctlr->irq);
[...]
118 			ctlr->rb = ialloc(sizeof(RingBuf)*ctlr->nrb, 0);
>119 			if(ctlr->ntb == 0

here's a wild stab in the dark which has bitten us for an embedded
kernel we run.  make sure to turn off legacy emulation for usb devices
in the bios.  (phoenix bios has this option in the second tab under one
of the bottom selections.)  legacy emulation can turn on system management
mode.  system management mode takes over system resources (like memory)
to run the emulation code and then puts things back.  the os is not
supposed to notice, but sometimes the emulation is not seemless.
(or perhaps we don't know all the magic spots in memory.)  either way,
it's worth a shot.

- erik