Hiya guys,

sadly Slackware 14.2 is EOL now, and I would just like to know, if the 15.0 binaries are backwards compatible ( no-kernel) to ARMv6?

How I remember, AARCH32 is as backward compatible to v4,5,6 as much as ARM V7 is.

The RazPi 1 has poor specs and is a very outdated box. It has no FPU to speak of , so everything has to be compiled 'Soft Float' = with maths instructions emulated. Slackware Arm 32bit handles the Pi 2 and more modern ones.

Slackware-15.0 is compiled 'Hard Float' using the FPU to run the maths instructions. No, the binaries are not compatible.

AFAIK, No 'soft float' updates beyond 14.2 are planned by the Slackware Arm guys. It's not worth the effort, frankly. I think the Slackware Arm guys will be quick to correct me if I'm wrong.

Back in 2000 I was called on to design a digital clock using a special prototype display and running on batteries. The bill came to €20,000, which was very cheap at the time. I used a PIC microcontroller programmed in Assembler. I designed a printed circuit board and had some pcbs built. I assembled & tested them myself. Now (with the exception of the batteries) the Pi 1 lets you do such projects for under €100. That's the strength of those early Raspberry pis.

The RPi clear back to model 1 (Pico excluded) had an FPU. It wasn't always used 11 years ago; Debian and derivatives used it, while Slackware et al. built the emulation instead. And this wasn't (yet) using NEON, just VFP.

But even back then, I... well, here.

Yes, it did, but it was a WIP. All distros that I know of have a 'soft float' 32bit version for Pi 0 & 1, and their hard float version covers the Pi 2 & later. Math Emulation is a gcc option. Either your FPU is 'SF' = emulated (all functions emulated) or 'HF' = used (No functions emulated). The 'HF' option wouldn't work on the Pi 1.

use ARMv5te

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Yes, it worked just fine in the first Raspberry Pi, using the Broadcom 2708/2835 processor.

My last raspberry pi sbc is the Pi 3B. I installed it using the mini rootfs and then rebooted with NFS enabled to pull down the rest of Slackware aarch64. Stuart and I did discuss what the minimum system hardware requirements would be for Slackware aarch64 next.

The raspberry pi 3 ran okay but it was a lot of extra work to install it. The slackware installer (setup) requires more than 1Gb of RAM to load the initrd (ramdisk). I tested on a Orange pi zero 2 (h616 soc) as well

It required me to unpack the initrd-armv8.img (ramdisk+ busybox + kernel stuff) and remove a ton of kernel modules so that the ramdisk can fit in RAM. I pared it down so much that the only supported filesystem available was ext4. Size was down to less than 200Mb.

So what Stuart and I recommend going forward is to purchase boards with at least 2Gb of RAM for future projects. You will save yourself a lot of headaches.

I have given you the received wisdom as I understood it. If you think HF compiles work on the Pi 1, go for it. Some of the later Pi 1s had Cortex A-53 cores and that should have an FPU. It certainly will not work on earlier models.

OTOH, if it goes belly up, maybe I was right.

Absolutely!

Anyway, I ordered a Raspberry Pi 4 plus an Argon ONE M.2 Case, incl a M.2 2TB SDD.

thanks

I was promising myself one of these 8 core RK3588 boxes, but by the time you buy the extras, you're in at the bottom end of X86_64 PCs. I'm also not going to be first in any more. I was with the RazPi 4, and got one of the first model B, with a Flirc case because the fan was louder than the sound. They improved it a lot since.

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