Hej! One of the most problematic issues with the whole 16-bit PCMCIA subsystem on the x86 architecture is the following: cards request iomem or ioport resources, but the PCMCIA subsystem does and can not know reliably at what addresses iomem and ioport resources may be used, without interfering with any third hardware.
Currently, we utilize two approaches to correctly "guess" which iomem and ioport resource areas are safe to use[*]: - If the PCMCIA bridge resides behind a PCI-PCI bridge or a PCI root bridge with specific memory or I/O windows, these resoruces -- if not registered otherwise -- are made available to PCMCIA devices. This works great on modern hardware, and hasn't caused us any major hassles since its introduction in 2.6.13 or so. - Userspace (pcmcia-cs or pcmciautils) parses /etc/pcmcia/config.opts and registers a couple of memory and I/O resources. This latter configuration file most often contains include port 0x100-0x3af include memory 0xc0000-0xfffff include memory 0xa0000000-0xa0ffffff And so Komuro (CCed) suggested to add these default resource entries to the kernel, so that it can later use parts of these resource areas to enable PCMCIA devices without userspace interaction. Do you think it would be safe to enable these areas by (kernel) default on x86? Of course, other entries in /proc/io{mem,ports} would be honoured, there would be a boot option to disable this feature, and some tests are run on the iomem and ioport resource areas. Best, Dominik [*] In addition, there are some tests which are run on iomem and ioport resources before marking them as available to PCMCIA devices, but let's ignore this aspect for the moment. _______________________________________________ Linux PCMCIA reimplementation list http://lists.infradead.org/mailman/listinfo/linux-pcmcia