Hello,
I may be the original poster of the article you mentioned.
The reason you cannot see the peripherals on the ISA bus is that as you say, they are not mapped. However, the ELan uses configurable chip select pins that can appear in memory or IO address space, so not only does the ISA bus have to be enabled but the CS pins also need setting up.
I began disassembling the Boot rom which sets up the GPIO memory windows and chip selects. An overview of my finding is at the link below
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To make further progress I have to continue disassembling the boot rom, but finding the enthusiasm to continue is difficult!
The 3315 contains a CL5400 LB vga chip but does not have much power to do anything really useful, so I was interested to find out about the OpenAP project below
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Since the hardware is very similar - in fact the 3315 contains extra bells and whistles, I wondered about converting the 3315 into a Wireless AP. However, to do this I need to at least find out what CS pins the 2MB flash program memory is connected to. The Boot rom already kindly sets up the peripherals and does nice system tests for us, so I wanted to keep the boot rom as is, which would allow us to go back to windows CE if we should so wish. This would mean placing the Kernel in the 2MB flash, and where the Boot rom expects the winCE kernel to be do some twiddeling to to get it to load, since the CE kernel expects to be in protected mode I believe, whereas the Linux kernel does not, something to do with head.s, setup.s or loader.s, cant remember
However, I appreciate this may be too difficult, so teh second option is to place the Alios loader in the boot rom, along with the VGA bios if we still need VGA. This means reprogramming the boot rom, which I assume is connected to the ROMCS0 chip select line, and placing the Kernel in the 2mb flash along with the rootfs either in the flash if there is enough space, or in the NAND flash if not, but all this requires more discovery work.
There is still work to do disassembling the Boot rom to find out what GPIO pins the NAND flash, CS4231 and Program Flash are connected to. Might I ask what link you shorted to get the ROMCS0 redirection for PCMCIA memory boot?
Contact me off line where I can tell you more about the Dissassembled boot rom.
Thanks, Vincent