[OpenBIOS] QEMU / OpenBIOS booting SunOS 4.1.3 / 4.1.4
parag at codegen.com
Wed Jun 7 04:13:52 CEST 2006
>This part seems very different on Sparc32. I did not know some weeks
>ago, but OpenBoot until very late versions does not use the client
>interface but a data structure called "romvec" (arch/sparc32/romvec.c)
>that contains several data pointers and callbacks to different OF
I haven't looked at NetBSD/Sparc, unfortunately. Just NetBSD/PowerPC
with Open Firmware support for Macs, old Moto stuf, etc, which makes
proper call-backs, plus has specs in nauseating detail.
Have you looked at the other BSDs (Free/Open) to see if their Sparc32
boot is any different, perhaps simpler?
>Interesting. Loading the kernel at once. The ELF kernel loads fine, but
>the CD comes with an a.out kernel that has a wrong "text" size and no
>data size. Since it loads directly from the CD device as opposed to from
>a filesystem I have no idea how much data to load and how to parse it.
Yeah, the first trick is building that ELF netbsd kernel and not the
bootstrap a.out thingie. A standard ELF kernel may lurk lower down on
the CD somewhere. Otherwise it's cross-compile time.
The SF trick short-circuits the loaders (at least initially) by
directly loading the ELF image, then passing it the magic args that it
expects. The args are hard-wired inside a C array, just to get things
rolling. Works surprisingly well for system bring-up.
>Does a version of Smart Firmware boot Solaris on Sparc? Any chance
>there's some hint?
Unfortunately the version of SF that boots Solaris contains a LOT of
proprietary Sun code, some in C, some in Forth/Fcode. Even we never had
a copy of it - it all stayed on Sun's machines.
The Solaris versions Sun's SF was booting involved loading and running a
variety of their Fcode loaders, which loaded other Fcode, which
sometimes loaded even more Fcode, which eventually loaded a kernel,
which would then run, making a bunch of callbacks all the while.
A variety of subtle bugs and bug-compatibility modes in the SF code are
#ifdef-ed SUN_COMPATIBILITY, but other than that, there's not much else.
/__)_ _ _ _ "What do you give a man who has everything?" the
/ (// (/(/ pretty teenager asked her mother. "Encouragement, dear,"
_/ she replied.
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