#1 2016-04-13 14:32:51

AltTabDelete

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Registered: 2016-04-12

Posts: 13

[NEVERMIND] PAE vs nonPAE for 32-bit kernels

As I understand it, the entire purpose of PAE is to enable the usage of =>4Gb RAM.

As far as I am aware, there are no nonPAE 64-bit kernels.

As far as I can tell, there are no motherboards capable of mounting => 4Gb RAM that are not 64-bit capable.

To the best of my knowledge, there are no motherboards requiring a 32-bit OS capable of mounting => 4Gb RAM.

According to Wikipedia, Banias Pentium-M CPU's are capable of running and using PAE, but will refuse to boot because their CPUID does not display the PAE flag.
Banias Pentium-M CPU's will run the i686 kernel if you can get them to boot.
( https://en.wikipedia.org/wiki/Physical_ … sion#Linux )

Prior to 14.04, Ubuntu & others used a 'fakepae' procedure to allow the Banias family of Pentium-M CPU's to boot.

For 14.04 and subsequent, Ubuntu uses a 'forcepae' boot option to allow the Banias family of CPU's to boot.

I don't know how many pre-Pentium Pro CPU's are still in use. I don't know how many Banias family Pentium-M CPU's are still in use, but I believe they were widely produced and distributed by Dell and in Thinkpads which were all produced in large numbers.

Given all this, might we consider whether we truly require a nonPAE 32-bit kernel (i586) for pre-Pentium Pro CPU's
or
whether we can more efficiently support only a PAE 32-bit kernel (i686) with a method of allowing Banias Pentium-M CPU's to boot?

As I am not technically capable of implimenting either solution, I defer to the community's judgement; I thought a discussion of the two options might be useful in terms of support.

Last edited by AltTabDelete (2016-04-14 15:55:49)

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Head_on_a_Stick

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Registered: 2015-09-29

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Re: [NEVERMIND] PAE vs nonPAE for 32-bit kernels

the entire purpose of PAE is to enable the usage of =>4Gb RAM

So repeat after me: PAE didn’t ever really fix anything. It was a mistake. It was just a total failure, and the result of hw engineers not understanding software.

So no, PAE does not mean that you can use more than 4GB of RAM. Even before PAE, the practical limit was around 1GB, and PAE didn’t move that post a fraction of an inch!

https://cl4ssic4l.wordpress.com/2011/05 … about-pae/

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AltTabDelete

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Registered: 2016-04-12

Posts: 13

Re: [NEVERMIND] PAE vs nonPAE for 32-bit kernels

While I defer to Linus's opinion on the concept of the usefulness of RAM =>1 GB, my concern is much more mundane. I want to be able to use my Banias Pentium-M notebook. I can boot either i586 or with OS configurations i686 kernels. The rest of the discussion for me is moot because I'm maxed out at 2 GB RAM.

The thrust of my question was whether i586 kernels are a current requirement for the hardware in use, or if support time and effort would be saved by enabling i686 kernels to be used by the Banias family of CPU's. I'm perfectly happy with either outcome.

My admittedly selfish concern is that support overhead for the i586 flavor would eventually cause it to be dropped.

I'm tickled pink to be able to run BL at all! :-)

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AndyMender

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From: Reincarnated in the UK :)

Registered: 2016-04-01

Posts: 49

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Re: [NEVERMIND] PAE vs nonPAE for 32-bit kernels

I personally own an Asus EeePC 701 netbook with the Intel Celeron M ULV 353 (Dothan-512) processor. Debian i386 works perfectly fine on that machine (installs and boots). Only through extrapolation may I assume that similarly BL i386 should work in combination with this Intel Celeron M processor. That being said, I cannot make claims regarding the Banias-512 series, which is a predecessor of Dothan-512.

I used to use a nonPAE kernel in the past and I don't see any advantage of a 32bit PAE-compliant kernel at all. Only Pentium 4 and some PowerPC Macs could handle up to 4GB RAM, but no more. Running a 32bit OS with the PAE kernel and more than 4GB RAM could most likely be only done on a 64bit processor, which in itself is sub-optimal.

The only reason for a 32bit PAE-compliant kernel I found so far was a badly designed 32bit EFI implementation forced onto a 64bit processor in netbooks (and old MacBooks).

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AltTabDelete

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Registered: 2016-04-12

Posts: 13

Re: [NEVERMIND] PAE vs nonPAE for 32-bit kernels

I believe I understand better what BL is now, having read a lot more of the forum entries.

BL=Debian Stable+Openbox

That leads me to believe that the kernels offered will coincide with Debian Stable; if Debian Stable changes so will BL. Correct me if I'm mistaken.

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Head_on_a_Stick

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From: London

Registered: 2015-09-29

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Re: [NEVERMIND] PAE vs nonPAE for 32-bit kernels

the kernels offered will coincide with Debian Stable; if Debian Stable changes so will BL.

That is correct.

BunsenLabs uses the standard jessie kernel.

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Para todos todo, para nosotros nada