PCMCIA/CardBus To USB Drivers On The Chopping Block With Linux 6.4

[ll1025]

PCMCIA cards are going to be around in aircraft and they will want a brand new kernel there is a catch here.

This is all academic because no critical system like that is going to run a non-RTOS, and they're certainly not running on a mainline kernel.

If this were an issue they could easily

• Buy extended support from RHEL (if they were running linux, which they aren't; RHEL 9 has support to 2034)
• Maintain an out-of-tree driver
• Pay a single dev $60k / year to merge and maintain a driver for this
• use an older release (very, very common in the airgapped spaces you describe)

EDIT: Also, I'm pretty sure updates (e.g. to latest kernel) would invalidate the aircraft's approvals / certifications, which makes this doubly moot. The systems relying on legacy hardware are also going to be stuck with legacy software-- which doesn't matter, because it's all going to be airgapped.

[oiaohm]

This is all academic because no critical system like that is going to run a non-RTOS, and they're certainly not running on a mainline kernel.
If this were an issue they could easily

EDIT: Also, I'm pretty sure updates (e.g. to latest kernel) would invalidate the aircraft's approvals / certifications, which makes this doubly moot. The systems relying on legacy hardware are also going to be stuck with legacy software-- which doesn't matter, because it's all going to be airgapped.

https://www.linux.com/news/linux-in-aerospace-a-personal-journey/

"Linux is already being used in flight-certified systems at level D"

Steven H. VanderLeest, Software Engineering Technical Lead at The Boeing Company

Yes that Boeing jets. Yes C Level parts are in newer Boeing jets using Mainline Linux kernel do exist.

https://www.consunova.com/do178c-info.html

DO-178 Level D software is software whose anomalous behavior, as shown by the system safety assessment process, would cause or contribute to a failure of system function resulting in a minor failure condition for the aircraft. Failure of DO-178 Level D software could be typified by minor injuries.

Level D can be logging systems the types of beasts that need the PCMCIA sram card. Also your presume is wrong. Updates to latest kernel depends on what level of critical the system is. C-E level can update the software without recertification.

There are aircraft with glass systems up to level B parts that are using mainline Linux kernel.

Lose all Level A you lose the aircraft controls or radio completely. Losing all your level B-D and down you are sitting in cockpit and you have controls but no navigation systems to tell you were you going or airspeed or anything else useful. Yes B-D could be all non-RTOS. A and B level parts need flight certification. C-E updates don't require new flight certification.

Level E you don't care about that would be entertainment systems and the like annoy customers but nothing todo with flying.

Aircraft cockpits every individual screen in there can be a completely different OS.

Yes your presumes that no critical system is going to run a non-RTOS os that comes down to the define of critical. Level B/C systems I do class fairly critical. Yes people presume more in a aircraft has to be certified than really has to be.

As I said in the new systems with Linux with PCMCIA these are Level D and C parts to the Linux part the PCMCIA appears as a normal USB storage device due to the reader/writer. So why in hell maintain out of tree driver the in kernel USB storage driver works. PCMCIA will be around but that does not mean there will be a need for Linux kernel drivers to use them.

[ll1025]

. So why in hell maintain out of tree driver the in kernel USB storage driver works. PCMCIA will be around but that does not mean there will be a need for Linux kernel drivers to use them.

I'm not clear what we're arguing about then, the entire point is that this removal is going to be irrelevant.

[oiaohm]

I'm not clear what we're arguing about then, the entire point is that this removal is going to be irrelevant.

I was answering the following like.

A lot of people just don't seem to realize just how old and obsolescent PCMCIA really is... and how finicky it could be, nor the unlikelihood of these old systems still being operational - and useful.

Like it or not PCMCIA is not obsolescent yet and its not only found in old systems. PCMCIA drivers are mostly stuffed. PCMCIA to PCI then though a PCI/PCIe adapter would be possible to find being used by some parties attempting to avoid the 500 to 3000 dollar a reader/writer problem.

Yes the cost of a PCMCIA to PCI with a PCI/PCIe bridge items is less than 400 dollars its the cheapest way to interface with PCMCIA sram cards and it also not a ruggised solution so you don't find this in the aircraft it self. This would be service center computers and possible forensics.

If the price of PCMCIA to PCI or PCI/PCIe bridge items go up a little or the cost of USB to PCMCIA read/writers comes down little the need for all the PCMCIA drivers would come pointless fairly quickly.

PCMCIA is going to be in use well have all the Linux kernel drivers for PCMCIA are absolutely pointless we are close to that point now.

PCMCIA is one of those wacky cases. Normally stuff is removed from Linux kernel when it use case has completely disappeared. PCMCIA use case still exists but the way we interface with PCMCIA is fairly much being replaced by usb readers/writers of PCMCIA. Think about it a malfunction PCMCIA card is better to crash a read/writer than the complete system in critical systems.

Yes this is a really rare case. I don't think I have seen talk about a technology remove from the Linux kernel for something that is in active use because the technology and the drivers normally go totally obsolete at the same time. PCMCIA the in kernels are going obsolete before the PCMCIA storage technology is.

So this is not your normal case.