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Comment by willvarfar | Hacker News Reader

Back a couple of years ago I messed up my MBP by partitioning it to dual-boot Linux.

At the time Linux desktops didn't cope with retina screens very well (and probably still don't?), but it was worth it for my code-heavy days. But I still went back into OSX for Skype-for-Business calls (shudder).

For ages I was very happy Linux-on-MBP user.

And then OSX refused to upgrade to the next major version because the ssd was partitioned.

So I'm kinda wary of ever doing any stunt like partitioning the internal ssd again in the future.

But reading about dual-boot from external SSD makes me think "when I get my M1, perhaps I can boot Linux from an external SSD". That way I can still use OSX for the MS Office Suite when the web-version isn't cutting it, kinda thing.

But is there any signing requirement for the external ssd boot-up?

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I've been booting Linux regularly from an external SSD since ~2016. This was after I encountered the same bs you did with it installed in an internal drive: I think I lost data when OS X upgrades first introduced logical partition containers in anticipation of APFS, and again when APFS was introduced.

Starting this year I no longer use Apple devices, since everything work-related I do in Linux.

I was using boot camp through that whole period and don’t think I lost a byte. I had time machine backups anyway. Maybe I used time machine restores as part of the migration though, I can’t remember.

Boot camp is different, though, since the installars are aware of that partitioning case.

When was that? I dual booted my MBP from 2015 or 16. UI scaling worked fine with a few exceptions using Ubuntu and Ubuntu GNOME.

> And then OSX refused to upgrade to the next major version because the ssd was partitioned.

IIRC with some MacOS update it got confused when it rebooted while installing, holding alt and choosing the correct partition while rebooting got it back on track.

You can disable the signing requirement, but it is unlikely that there will be Linux drivers for the M1's GPU any time soon.

I imagine the first person getting Linux booting at all (even without graphical acceleration) on the M1 will be at the top of HN.

Might be this person: https://www.patreon.com/marcan/posts

Apple support document on turning off secure boot: https://support.apple.com/en-us/HT208198

Does it work the same for M1 Macs?

Because the documentation only mention Intel CPUs with T2 chips.

Okay I just went and took a look...

Indeed it doesn't show the same options. This is what I saw when I went to Startup Security Utility:

(*) Full Security: Ensures that only your current OS, or signed operating system software currently trusted by Apple, can run. This mode requires a network connection at software installation time.

( ) Reduced Security: Allows any version of signed operating system software ever trusted by Apple to run. [ ] Allow user management of kernel extensions from identified developers [ ] Allow remote management of kernel extensions and automatic software updates

There's no option to turn on or off a firmware password, instead I had to login with a local administrator account first before I could access anything under recovery options.

There doesn't appear to be a way to set "No Security" as an option either. At least from the GUI. Maybe it's possible from Terminal somewhere. But it seems unlikely or undocumented for now.

Edit: Here's the Apple documentation on this: https://support.apple.com/en-us/guide/mac-help/mchl768f7291/...

Regarding kernel extensions, there's also https://support.apple.com/en-us/HT210999 and https://support.apple.com/en-us/HT211860

Regarding macOS Recovery, there's https://support.apple.com/en-us/guide/mac-help/mchl82829c17/...

It's possible through the GUI, although it's convoluted and I think you first need to disable SIP? I am sure bputil should be able to do it as well.

I'm pretty sure most Linux desktop environments these days have decent support for UI scaling. Last time I tried it worked well if your dpi was close to an integer multiple of 96. And if external boot works well with the M1 Macs, a thunderbolt enclosure with an m.2 drive would be pretty darn fast.

If you had problems with retina screens a couple of years ago, that was probably due to the drivers for the MBP GPU, not due to monitor resolution or due to Linux.

There are more than 5 years since I do not use monitors with less than 4k resolution with Linux and I never had any problems with correct scaling or with anything else.

While the NVIDIA drivers are not open-source, nevertheless they usually have the best Linux support and they have no problems with multiple high-resolution monitors. However, Apple does not use NVIDIA, so that increases the chances for problems on Linux.

For the smaller MBPs, with Intel Iris GPUs, the GPU drivers should also have been OK, even a couple of years ago.

The greatest chances of problems would have been on MBPs with AMD GPUs. Nevertheless, the AMD drivers have been improving during the last years, so today there should be better chances that they would work OK.

>And then OSX refused to upgrade to the next major version because the ssd was partitioned.

Apple pretty clearly don't mind you partitioning the SSD because you need to do that for bootcamp, which is supported (for Intel Macs at least). I'm not sure exactly what issue you had, but it's not a case of Apple saying "no, you can't do that".

Regarding display scaling: it's been working well for me in Fedora (X-Window + KDE) for a few years now, on a 13.3" FullHD laptop (scale set to 118%) and a workstation with 4K 24" monitor (scale 175%). Just had to manually increase mouse cursor size and set the "Force font DPI" value higher.

Just so you know, you can always recover this kind of thing by booting while holding cmd + r and then formatting the drive and reinstalling.

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