SIL3112 vs SIL3512 (miniPCI/PCI sATA)

[DiTBho]

What's the difference? It's not clear to me.
Anyone has low level experience with these chips?
If so, is there any PNP or quirk with the PCI?
miniPCI and PCI SIL3*12 cards also have an onboard FLASH (512Kbyte)
What is the FLASH for?

[mariush]

bios extensions / firmware (ex maybe to configure hardware raid in case of SIL3512) , eeprom for hardware IDs (custom hardware ids if you want to brand the controller to your company)

See http://www.pix.net/techpubs/silicon_image/SiI-DS-0102-D.pdf
page 9
• Supports up to 4-Mbit external flash or EPROM for BIOS expansion.
• Supports an external EEPROM, flash or EPROM for programmable device ID, subsystem vendor ID,subsystem product ID and PCI sub-class code.
• Supports the Silicon Image specific driver for special chip functions.

page 34

Auto-Initialization
The SiI3512 supports an external flash and/or EEPROM device for BIOS extensions and user-defined PCI configuration header data.
Auto-Initialization from Flash
The SiI3512 initiates the flash detection and configuration space loading sequence upon the release of PCI_RST_N. It begins by reading the highest two addresses (0x7FFFF and 0x7FFFE), checking for the correct data signature pattern — 0xAA and 0x55, respectively. If the data signature pattern is correct, the SiI3512 continues to sequence the address downward, reading a total of sixteen bytes. If the Data Signature is correct (0x55 at 0x7FFFC), the last 12 bytes are loaded into the PCI Configuration Space registers.
Note: If both flash and EEPROM are installed, the PCI Configuration Space registers will be loaded with the EEPROM’s data. While the sequence is active, the SiI3512 responds to all PCI bus accesses with a Target Retry.

etc etc
Seems like the expansion rom starts at 0x30

[DiTBho]

Thanks!

I am trying to understand
- why PowerMacs do need to re-program the FLASH of SIL3112-based PCI-sATA adapters
- to properly work with MacOS-v{ 10.1 .. 10.4 }
- specifically what the FLASH does on PowerPC with oForth (Mac-firmware)
- why GNU/Linux on MIPS routers(1) don't recognize miniPCI SIL3122-based PCI-sATA adapters
- if SIL3112 can operate without a FLASH
- if this makes it work on MIPS routers
- if not, what I can modify/hack(1) to make it work on MIPS routers
- if not, if I have to give up with miniPCI/sATA and think about a different approach


I will read and study the doc. Thanks 



(1) I have manually configured the kernel and included all the support.
Other miniPCI cards (e.g. quad uart, firewire) do work, while ... sATA cards do not

(2) is it a PCI-config space issue? can it be fixed?
is a different kind of problem? can it be fixed? ...