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Re: [Qemu-ppc] Apple's BootX
From: |
Programmingkid |
Subject: |
Re: [Qemu-ppc] Apple's BootX |
Date: |
Fri, 26 Jan 2018 10:37:29 -0500 |
> On Jan 26, 2018, at 3:32 AM, Jd Lyons <address@hidden> wrote:
>
>
>
>> On Jan 25, 2018, at 10:18 AM, Programmingkid <address@hidden> wrote:
>>
>>
>>> On Jan 25, 2018, at 10:01 AM, Jd Lyons <address@hidden> 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?
>>
>> Have you tried adding "-prom-env boot-args=-v" to QEMU's arguments yet?
>
> Yes, I usually use -prom-env 'boot-args=-v debug=0xffe kdp=2’.
>
> On a real PPC Mac BootX seems to give some extra debug in fo with command+V,
> tho most of the time it goes by so fast that it’s unreadable. Booting from a
> slower drive like USB yield the kind of info I’m looking for, to be able to
> tell at what stage BootX is hanging.
>
> Unfortunately, this debug info is no sent to the screen, or stdio in
> OpenBios, or I just haven’t figured out how to do that yet.
There is another way to see what boots sends to the screen. That is to record
the output of the screen. I use to do this when I had to read the output from
Mac OS X when it was booting. I used Quicktime X to record the screen. Since
you are on Linux there may be other options. You could take the output of your
computer and send it to a a DVD recorder, VCR, DVR, Camcorder, etc... You might
even want to try aiming your camera phone at the screen and record what Bootx
is displaying.
https://itsfoss.com/best-linux-screen-recorders/
This page list several programs that can record your screen on Linux. I just
don't think it would help on a PowerPC Mac.
- [Qemu-ppc] Apple's BootX, Jd Lyons, 2018/01/25
- Re: [Qemu-ppc] Apple's BootX, Programmingkid, 2018/01/25
- Re: [Qemu-ppc] Apple's BootX, Jd Lyons, 2018/01/26
- Re: [Qemu-ppc] Apple's BootX,
Programmingkid <=
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, Jd Lyons, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, BALATON Zoltan, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, Programmingkid, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, Jd Lyons, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, Programmingkid, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, Jd Lyons, 2018/01/27
- Message not available
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, Jd Lyons, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, BALATON Zoltan, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, Jd Lyons, 2018/01/27
- Re: [Qemu-ppc] [OpenBIOS] Apple's BootX, BALATON Zoltan, 2018/01/27