[OpenBIOS] Sparc64 memory allocation problem

Blue Swirl blauwirbel at gmail.com
Tue Aug 24 23:41:30 CEST 2010

On Tue, Aug 24, 2010 at 9:19 PM, Mark Cave-Ayland
<mark.cave-ayland at siriusit.co.uk> wrote:
> Blue Swirl wrote:
>> The problem was that ELF loader didn't allocate the areas. Now with
>> r858 OpenBSD gets into kernel:
>> Loading FCode image...
>> Loaded 4893 bytes
>> entry point is 0x4000
>> OpenBSD IEEE 1275 Bootblock 1.1
>> ..
>> Jumping to entry point 0000000000800000 for type 0000000000000001...
>> switching to new context: entry point 0x800000 stack 0x00000000ffe02b59
>>>> OpenBSD BOOT 1.2
>> Trying bsd...
>> Booting cdrom:f/bsd
>> 2590536 at 0x1000000+3236576@0x1800000+957728 at 0x1b162e0
>> symbols @ 0x200241c0 36 start=0x1000000
>> CHAINprom_get_msgbuf: test failed
>> prom_get_msgbuf: allocated new buf at ffffffff
>> prom_get_msgbuf: claiming new buf at ffffffff
>> Unhandled Exception 0x0000000000000032
>> PC = 0x0000000001080bc4 NPC = 0x0000000001080bc8
>> Stopping execution
>> I noticed that MilaX had problems with allocation happening, so I made
>> the loader ignore the failures. That is probably not correct.
> Re-reading the IEEE-1275 spec again, I'm thinking that what we have at the
> moment is wrong. To quote from the definition of the "load" command:
> If the “load” method succeeds, and the beginning of the loaded image is a
> valid client program header for the system, allocate memory at the address
> and of the size specified in that header, move the loaded image to the
> address, and perform the function of init-program to initialize
> saved-program-state so that a subsequent go command will begin execution
> of that program.
> This sounds to me as if "load" as opposed to "init-program" should do the
> relocation if pointed at an ELF file (allocating memory as necessary),
> otherwise as in the case of the Solaris Fcode loader and the BSD source
> given above then all memory setup is managed by the loader itself. Hence the
> invocation of "init-program" is practically a no-op since the memory
> allocations should be already handled.
> If you quickly rearrange elf_load.c in this way, does that solve the boot
> problem for both openBSD and Milax?

I don't think so, OpenBSD crashes again when clearing BSS. Milax is unchanged.

I moved ofmem_claim() call to load_segments().

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