H2500 SN Bios Flash

[Jackhead]

With the great Pikuma tutorial for PS dev i setup my PS Dev PC new.
Im looking to use the h2500 with the best option for IDE and debugger.
ATM i using the Code Warrior release 5 with update DECI and it working fine with win98se.

Whats new for me that its possible to flash a SN bios to the h2500 to use it with the SN Win Debugger like the PSY-Q Kit.
I had a SN Flash but when i try to flash it just freeze the h2500.
Reflash the DECI or H25bios anything working fine again.
But i have no idea why the SN bios dont work at all?? Anyone tryed this here before?
From what i read the SN Windebugger even work on WindowsXP with the h2500, what im want to try..

[nocash]

Can't help there. But I am curious: What is in those memory chips? As far as known, the DTL-H2500 has two memory chips,

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  IC807-2 32pin MX 27C1000MC-90 (PROM)
  IC808   32pin F 29F040A-90    (FLASH)

I assume the 512Kbyte FLASH is equivalent to the BIOS/Kernel in retail consoles, perhaps with some modifications and different CRC32?
And the 128Kbyte PROM, I've no idea what it's good for... does it contain additional MIPS code, or other code or data?

[Jackhead]

i have no idea.

the flashing working now. system was needed a reboot.
But the sn windebugger dont see the h2500. Flashed with h2500.img(SN) V1.3
Maybe i need another version or its windows nt only.. Very confusing and no docs.

[nocash]

Going by the viewtopic.php?f=69&t=56 BIOS Collection thread there aren't any known DTL-H2500 bioses, but ...

Going by the above posts there are at least three DTL-H2500 bioses...
- a SN bios
- the DECI
- H25bios
Does somebody know where those BIOSes come from, are they included in a SDK package?

[Jackhead]

The DECI and h25bios are include the Programmer Tools under PSSN. The PSY-Q SN bios for SN Software comes from SN. I think its also include in some Lib update discs.

[nocash]

I've looked through the files on the Programmer Tool CDROMs. And, yes, it's rather difficult to extract the BIOS ROM-images from there. There are at least two different file formats (neither one being raw ROM-images), and different BIOSes for different purposes, and different CDROM versions (which have the files in different locations, like older PSYQ folder, or newer PSSN folder, and maybe (I haven't checked) different BIOS revisions on different CDROMs).

What is there...
In particular, these files on the Programmer Tool CDROM seem to contain BIOSes:

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PSYQ\PFLASH.BAT\KERNEL.BIN,KROMGDAT.BIN,KROMDAT.BIN,SN.BIN --> on older CDROMs in PSYQ folder
3RDPARTY\METROWER\DECI\FLASH25\H2500.IMG
PA\DTLH2700\H2700*.BIN --> Performance Analyzer BIOSes for PAL and NTSC
PSX\BIN\DTLH2500\H25DRV\H25*.IMG
PSSN\BIN\DTLH2500\H25BIOS\H2500.IMG
PSSN\WINDEBUG\PFLASH\KERNEL.BIN,KROMDAT.BIN,KROMGDAT.BIN,SN.BIN

The KERNEL.BIN,KROMDAT.BIN,KROMGDAT.BIN,SN.BIN files contain the kernel, gui, fonts, and are apparently used to compose the final ROM-image on the fly.

Most of the .IMG files seem to be PSX EXE files, which should apparently reflash the BIOS when executing them on the console. Examining that files in an emulator/debugger isn't so easy because they to require more than 2Mbyte RAM (in particular, they are loaded to a memory location that would contain the CPU STACK in retail consoles).

I dont know if any of those files contains "the whole" 512Kbyte BIOS image, or if they do all contain unused memory sections with uninitialized data (so any attempt to dump the BIOS would include leftovers from previous BIOS versions). Although, there's that CLEANMEM binary (in COFF format) that seems to be used to remove leftovers, but I don't know if it's 00h-filling or FFh-filling everything or whatever else.

Could it be dumped...
The easiest way would be to reflash the BIOS, then remove the FLASH chip, and dump it with external tools, like eprom burners. Alongsides, one could also dump that mysterious EPROM chip (it might be something related to the debugging hardware, or if it's similar to the DTL-H2000, then the EPROM might contain the "real" bootrom, which would then switch to the updated FLASH firmware at some point after booting).

One could perhaps use the debugger to dump the FLASH content (but as far as I understand, the debugger stops working when not having the "correct" BIOS version installed). Or use some old-fashioned "copy BIOS to memory card" tools (if that's easier).

Dumping the version string...
Normally, there is an ASCII version string at address BFC7FF32. I guess that small memory snippet could be easily viewed in the DTL-H2500 debugger?

I am curious if that string exists at all, and if it does change for PAL/NTSC mode (and if it changes in different BIOS versions, but that does probably bring up problems with the debugger not working with wrong BIOS versions).