04 Jan 2021, 20:25

SSD Rochade

My desktop PC has two NVMe drives, one for Windows and one for NetBSD. With Steam game footprints being what they are, the Windows one (256 GB) has been perpetually overfull, so it was time for something bigger.

At the same time, I had bought an NVMe daughter board for my Pinebook Pro. My impression with the PBP is that the I/O performance of the eMMC module is holding it back, so I am excited to give it fast storage :)

This presents an opportunity to change over the drives in a “rochade”:

  1. Remove the NetBSD drive, add empty drive.
  2. Add GRUB bootloader, copy over Windows installation.
  3. Move old SSD into the laptop, re-add NetBSD drive.

What’s nice about this is that at any point in time, one can roll back the process, so the chance of losing data is small.

This post is about some things I learned in the process.

Moving Windows 10 to a new drive

Some Googling told me that the simplest way of moving an existing Windows 10 installation to a new drive is something called System Image Restore. First, you need to create an image of the existing C: drive onto yet another storage medium – an external hard drive in my case. Then, you boot from a rescue USB stick, such as the one from the retail Windows packaging, and restore the image.

It turns out that this feature is somewhat deprecated and hidden; its code was evidently last touched in the days of Windows 7. It is hidden in the “Backup” tab of the system settings under the heading “Searching for an older backup?":

Backup Settings

Once there, hit the “Create system image” link on the top left:

Link @ top left

Now, when it came time to restore the image to the new disk, I learned something important about the process:

You cannot restore to a different disk if the original disk is also present.

This means that you must disconnect the old drive first. Before we come to the other thing I learned, we need to talk about partition tables and (dual-)booting.

EFI, GPT, MBR, GRUB, etc.

In modern PCs, there are two fundamentally different ways to partition the boot drive and to boot the system:

MBR and BIOS: there is a “classic” partition table (also called an MBR partition table). It has space for four entries (“primary partitions”). One of these may be an “extended partition” that can contain further partitions. The first 512 bytes on the drive, the Master Boot Record, contain the start of the bootloader. The bootloader is executed in real mode, which means that your modern CPU pretends it is an 8086 from roughly 1982. In this scheme, NetBSD uses a single partition and places a disklabel at the start. Then, the partition can be further subdivided through the entries in the disklabel.

GPT and UEFI: UEFI, the Universal Extensible Firmware Interface, is a modern-ish standard for writing bootloaders and such. Contrary to the BIOS, it offers modern features such as 32- or 64-bit addressing on the CPU. The partition table format used for UEFI booting is called GPT (GUID partition table, where GUID is a Globally Unique Identifier). GPTs are also more modern. They have space more entries (often 128) and no longer use the obsolete cylinder/head/sector addressing. Each partition has a type, a UID and optionally a label – a name that you choose and that you can use to identify the partition in /etc/fstab and elsewhere. The bootloader is on a partition of type “EFI System”, formatted with a vFAT (“msdos”) file system.

Of note is that UEFI and GPT are used on other platforms as well: For instance, modern ARM systems (such as the Pinebook Pro) have a UEFI bootloader and use GPT partitioning. There are also some MIPS systems using UEFI, and more. Depending on the age of the PC, there is either a choice between BIOS and UEFI boot, or UEFI is mandatory. –

My PC is from 2016, so both ways are supposed to work. In my old setup, I used GRUB (the GRand Unified Bootloader) to show a boot menu and boot either Windows or NetBSD, using its i386-pc architecture, i.e. BIOS boot.

To set up a GRUB partition, I booted from a grml.org Linux live system and ran the grub-install command, after creating and mounting a Linux MBR partition. To my surprise, it defaulted to a UEFI version of GRUB. Thus, I re-did the partitioning using a GPT (through cgdisk) and installed GRUB:

mkfs.msdos /dev/nvme0n1p1
mount /dev/nvme0n1p1 /mnt
grub-install --efi-directory=/mnt /dev/nvme0n1

Rebooting gave me a GRUB shell in a tiny, barely readable font on my 4K screen. Surprise: Manually booting NetBSD resulted in an error message

No suitable video mode found. Booting in EFI blind mode.

And there was no more console output from NetBSD. If someone reading this article knows how to fix this, I would be glad for a tip :)

One Windows restore later …

Next, I booted from the Windows install / rescue stick. In the second screen, I selected “Repair your computer”, then “System Image Restore”.

Keeping in mind that the image was created on a system with BIOS boot, I was nonetheless surprised at what happened to the drive:

  • The GPT partition table was gone, instead there was an MBR partition table.
  • Windows reserved three out of four primary partition entries for itself (system, C: and a hidden “rescue” partition). The EFI partition was moved, no longer mountable and turned into a 0x83 (Linux) partition type.
  • Reset boots straight into Windows.
  • My favorite dysfunction: The rescue and Linux partition were relocated to the start of the free space, preventing extending the C: drive with the free space – the very reason I had gone through all this hassle.

I fixed the latter issue by deleting and recreating the GRUB partition (see below) as well as moving the Windows “rescue” partition thing using gparted on grml.

GRUB install the second

This time, I created a new primary partition (entry #4) of type 0x83 (Linux), formatted it as ext2 and installed GRUB:

mke2fs /dev/nvme0n1p4
mount /dev/nvme0n1p4 /mnt
grub-install --boot-directory=/mnt --target=i386-pc /dev/nvme0n1

At this point, I also populated /mnt/grub/grub.cfg with the contents of the boot menu.

And this actually worked!

Addendum: Now, Windows no longer shuts down correctly, no idea what’s up *with that. Rebooting does the right thing though.

04 Jul 2020, 14:53

Using CPU Subsets for Building Software

Like many ARM CPUs, the one in the Pinebook Pro has a “big.LITTLE” architecture, where some cores are more powerful than others:

[     1.000000] cpu0 at cpus0: Arm Cortex-A53 r0p4 (v8-A), id 0x0
[     1.000000] cpu1 at cpus0: Arm Cortex-A53 r0p4 (v8-A), id 0x1
[     1.000000] cpu2 at cpus0: Arm Cortex-A53 r0p4 (v8-A), id 0x2
[     1.000000] cpu3 at cpus0: Arm Cortex-A53 r0p4 (v8-A), id 0x3
[     1.000000] cpu4 at cpus0: Arm Cortex-A72 r0p2 (v8-A), id 0x100
[     1.000000] cpu5 at cpus0: Arm Cortex-A72 r0p2 (v8-A), id 0x101

The A72 is a more powerful than the efficiency-oriented A53, it has out-of-order execution, plus it reaches a higher maximum clock rate (1.4 GHz for the A53 and 2.0 GHz for the A72 in the Pinebook Pro).

On NetBSD-current, the kernel scheduler prefers the big cores to the little ones. However, when building software, you may want to force the build process onto the big cores only. One advantage is that you still have the little cores to deal with user input and such, yet your build has the highest performance. Also, building with all cores at the highest clock rate will quickly lead to overheating.

NetBSD has a somewhat obscure tool named psrset that allows creating “sets” of cores and running tasks on one of those sets. Let’s try it:

$ psrset
system processor set 0: processor(s) 0 1 2 3 4 5

Now let’s create a set that comprises cpu4 and cpu5. You will have to do that as root for obvious reasons:

# psrset -c 4 5
1
# psrset
system processor set 0: processor(s) 0 1 2 3
user processor set 1: processor(s) 4 5

The first invocation printed “1”, which is the ID of our new processor set. Now we can run something on this set. Everything run below only sees two cores, cpu4 and cpu5. Note the “1” in the command below. This is the ID from before.

# psrset -e 1 make package-install MAKE_JOBS=2

If you run htop or similar while your package is building, you will see that only cpu4 and cpu5 are busy. If you have installed estd to automatically adjust CPU clocks, you will notice that cpu4 and cpu5 are at 2 GHz while the four little cores are running at a cool 400 MHz.

20 Jun 2020, 18:09

Getting Started with NetBSD on the Pinebook Pro

If you buy a Pinebook Pro now, it comes with Manjaro Linux on the internal eMMC storage. Let’s install NetBSD instead!

The easiest way to get started is to buy a decent micro-SD card (what sort of markings it should have is a science of its own, by the way) and install NetBSD on that. On a warm boot (i.e. when rebooting a running system), the micro-SD card has priority compared to the eMMC, so the system will boot from there.

As for which version to run, there is a conundrum:

  • There are binary packages but only for NetBSD-9. On -current, you have to compile everything yourself, which takes a long time.
  • Hardware support is better in NetBSD-current.

The solution is to run a userland from NetBSD-9 with a NetBSD-current kernel.

As the Pinebook Pro is a fully 64-bit capable machine, we are going to run the evbarm-aarch64 NetBSD port on it. Head over to https://armbsd.org/arm/ (thanks, Jared McNeill!) and grab a NetBSD 9 image for the Pinebook Pro. Then (assuming you are under Linux), extract it onto the memory card with the following command:

zcat netbsd-9.img.gz | dd of=/dev/mmcblk2 bs=1m status=progress

Be sure to check that mmcblk2 is the correct device, e.g. by examining dmesg output! Once the command is done, you can reboot. Once booting is finished, you can log in as root with no password. The first thing you should do is to set one, using passwd.

To the eMMC!

Would you like to replace the pre-installed Manjaro Linux on the eMMC?

It makes sense to have your main OS on the built-in storage, since it is quite a bit faster than the typical micro-SD card. In my tests, I get write speeds of about 70 MiB per second on the eMMC.

By the way, if you want more and even faster Storage, PINE64 will sell you an adapter board for adding an NVMe drive (a fast SSD).

Once you have booted NetBSD from the memory card, mount the Linux volume and copy over the image file from before, then unmount and extract it in exactly the same way as above. The only difference is that the target device is called /dev/rld0d. Shut down the system, remove the memory card, switch it back on and watch NetBSD come up :)

Getting a -current Kernel

To have better driver support, I recommend installing a NetBSD-current kernel. To do that, you just need to replace the /netbsd file with the new kernel – no changes to the bootloader are required.

You can find a pre-built kernel under https://nycdn.netbsd.org/pub/NetBSD-daily/HEAD/latest/evbarm-aarch64/binary/kernel. Download the file and install it:

cp /netbsd /netbsd.old
gunzip netbsd-GENERIC64.gz
install -o root -g wheel -m 555 netbsd-GENERIC64 /netbsd

You will find that there is now a driver for the built-in Broadcom Wi-Fi (as the bwfm0 interface) but the firmware is missing. To fix this, download the base.tgz set from the same location and extract the firmware blobs only (as root):

cd /
tar xvpfz /path/to/base.tgz libdata/firmware

In my experience however, the Broadcom Wi-Fi driver is extremely likely to make the system crash or hang. I tend to rely mostly on an old Apple Ethernet-USB adapter (an axe interface).

NOTE: I have since back-pedaled and returned to NetBSD 9. Other than the unstable Wi-Fi, I also had crashes when running npm install and other issues.

31 May 2020, 16:04

Pinebook Pro, First Impressions

Note: This post was written on the Pinebook Pro :)

After seeing it in action at FOSDEM (from afar, as the crowd was too large), I decided to buy a Pinebook Pro for personal use. From the beginning, the intention was to use it for pkgsrc development, with NetBSD as the main OS. It was finally delivered on Thursday, one day earlier than promised, so I thought I would write down my first impressions.

If you have never heard of the Pinebook Pro: It is a cheap, open, hackable laptop with an ARM processor, the successor of the original Pinebook (which I thought was too low-end to be a useful daily driver) with generally more premium components.

As I alluded to in the first paragraph, the enthusiasm of the Free Software community is incredibly strong! Nothing showed this better than the incredible resonance from a tweet with a quick snapshot after the first boot:

You’ll note, in passing, that on the photo, I am downloading the NetBSD install image :)

What makes this device attractive, apart from the price, is the ARM architecture without the baggage of the PC world. What’s more, an open and hackable system in the age of Macbooks with soldered everything, tablets that you cannot open, “secure” boot that severely limits what you can run on it, is something of a counterculture device. The Pine64 folks have built a great community that embodies the true hacker spirit.

The Hardware

Here is where I am going to be harsh: in some ways, using this device feels like a regression.

I was previously using a Samsung Chromebook Pro, a Pixelbook and a Pixel Slate as laptops. Compared to these, the Pinebook Pro has

  • no HiDPI screen,
  • no touchscreen,
  • a barrel connector power supply,

and peripherals are mostly using USB-A port. To be fair, there is USB-C, and it can be used to charge the machine, so I haven’t used the original charger yet.

The display resolution is 1920x1080, equivalent to about 100 dpi. While I regret the absence of HiDPI, it is well lit and well readable. The viewing angles are fairly large, and the colors are crisp. The default Manjaro Linux wallpaper is a great showcase for this.

The Pinebook Pro is vaguely shaped like a MacBook Air from a few years ago, with the same curved bottom. At 14", it is surprisingly large – the machines mentioned above are 12 to 13". Compared to the MacBook and Pixelbook in their quest for ever thinner devices, the Pinebook Pro feels strangely empty. I guess there is actually free space on the inside that you can use for upgrades and such.

The most similar laptop I have used is the HP Chromebook 14. Against this, the Pinebook Pro holds up really well though: it is lighter, has a better keyboard and display and is actually cheaper!

Keyboard and Trackpad

The keyboard is an absolute joy to use. Really, it’s great. The keys have a large amount of travel, comparable to older MacBook Pros, before they introduced the terrible keyboard. The layout (I have ANSI, i.e. US) is exactly what you would expect. This is definitely made for typing a lot.

On the other hand, I am not friends with that trackpad. I am hoping I can get used to it at some point. The way it tracks small finger movement is … weird and counter-intuitive, and I am having a hard time hitting small click targets. It has two mouse buttons under the bottom left and bottom right, so clicking in the middle usually has no effect. For dragging, you need to keep one finger in the corner on the button and move another finger, which sometimes triggers multi-touch gestures.

Battery life

I have not done detailed measurements, but it seems pretty good at about 7 hours. Here is the envstat output while writing this:

                               Current  CritMax  WarnMax  WarnMin  CritMin  Unit
[cwfg0]
            battery voltage:     3.935                                         V
            battery percent:        79                                      none
  battery remaining minutes:       319        0        0        0        0  none
[rktsadc0]
                        CPU:    42.778   95.000   75.000                    degC
                        GPU:    43.333   95.000   75.000                    degC

Performance

Compared to all those ARM SBCs I have used (Raspberry Pi, Orange Pi, Pine-A64), the Pinebook Pro feels really fast. Storage (at this point I am using a memory card) is decent speed-wise, and compilations are reasonably fast – though my five year old Intel NUC with an i7 still beats it by far, of course. But my workload involves compiling lots of stuff, so this seems like a good fit.

Graphics performance has not blown me away. Animations on Manjaro stutter a bit, Midori on NetBSD (the first browser that I tried) is really testing my patience.

Hackability?

I noticed that opening the bottom of the housing is screwed on with standard Philips head screws and easy to open. There are no rubber feet glued on top of the screws, no special tools needed.

You can easily boot your custom OS from the micro-SD card reader. As mentioned, I bought this machine for running NetBSD on it, which works well.

There are upgrade kits available, for example an adapter to add an NVMe disk instead of the eMMC. For the original Pinebook, there has been an upgrade kit with a better processor even.

Because we are on ARM, there is no “Intel Inside”, and consequently, there are also no stickers, except for one on the underside that gives the model number.

Conclusion

This has become longer than I intended. Despite my criticism, I really like this machine. I am hoping I can get some good development work done with it and use NetBSD for my daily computing tasks.

Stay tuned for another post with some NetBSD tips!