[OpenBIOS] Apple's BootX
Mark Cave-Ayland
mark.cave-ayland at ilande.co.uk
Thu Jan 25 22:52:50 CET 2018
On 25/01/18 15:01, Jd Lyons via OpenBIOS wrote:
> In an effort to figure out why qemu-system-ppc hangs at BootX when using
> some emulated and KVM CPU’s, I suppose it would be good to enter some
> breakpoints in the code.
>
> I found some BootX sources at:
>
> https://opensource.apple.com/tarballs/BootX/
>
> Tho I’m not sure what versions correspond to which release of OS X?
>
> And it’s not clear how to build them, tho I haven’t tried yet.
>
> I found some info on BootX as well as some idea how to do what I’m
> looking to do:
>
> https://people.ffii.org/~zoobab/bh.udev.org/filez/apple/mac6100/BootX.pdf
>
> *There are few other useful debugging tech- niques. Setting "auto-boot?"
> to false will cause the system to enter the OpenFirmware User In-
> terface by default. Changing kFailToBoot to 0 in include.tproj/sl.h will
> alter BootX’s default be- havior on error, so that it will return to
> Open- Firmware. Finally, calling Enter(), will cause BootX to drop back
> into the OpenFirmware User **Interface. This can be used as a break
> point. The "dumpl" word will dump some memory, by en- tering the
> address, then the length, then "dumpl". By calling printf in BootX
> immediately before En- ter(), the address can be easily determined, and
> the variable can then be examined and altered from OpenFirmware. Finally
> typing the "go" command will resume BootX’s execution. *
>
>
> I noted when I boot from boot usb0/disk:3,\\:tbxi while holding
> command+v BootX sends some info to the screen, seemingly via open
> firware, while displaying the “Apple Logo” boot graphic. The info show
> some of the boot process and what stage it’s loading” loading
> mach_kernel’ “ loading the .mkext”
>
> It would be nice to get this output going via Open Bios, if anyone has
> any idea how I might be able to do that?
Steve Troughton-Smith has previously custom built BootX from source in
order to boot older versions of Rhapsody (see
https://www.emaculation.com/forum/viewtopic.php?f=34&t=7047&start=1375#p55205
and https://github.com/steventroughtonsmith/BootX for more information).
If the instructions in the forum post don't give enough detail then it
might be worth a direct email?
ATB,
Mark.
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