Diff for /wikisrc/ports/evbarm/raspberry_pi.mdwn between versions 1.103 and 1.143

version 1.103, 2018/11/06 22:29:26 version 1.143, 2021/02/24 08:31:25
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 [[!meta title="NetBSD/evbarm on Raspberry Pi"]]  [[!meta title="NetBSD/evbarm on Raspberry Pi"]]
   
 This page attempts to document and coordinate efforts towards NetBSD/evbarm on [Raspberry Pi](http://www.raspberrypi.org).  All [board variants](https://en.wikipedia.org/wiki/Raspberry_Pi#Specifications) are supported.  We use e.g. "RPI2" to refer to "Raspberry Pi 2" to save precious bytes on this page.  This page describes the NetBSD/evbarm port on [Raspberry Pi](http://www.raspberrypi.org) hardware.  All [board variants](https://en.wikipedia.org/wiki/Raspberry_Pi#Specifications) earlier than the RPI4 are believed supported, and specific boards known to work are listed.  We use e.g. "RPI2" to refer to "Raspberry Pi 2" to save precious bytes on this page.
   
 Initial, limited, Raspberry Pi support was introduced in NetBSD 6.0. NetBSD 7.0 adds complete support for the board, along with introducing support for the quad-core Raspberry Pi 2 board.  Raspberry Pi 3 support was added for NetBSD 8, and backported to NetBSD 7 in July of 2017.  (This page assumes those using NetBSD 7 are using 7.2, or the netbsd-7 branch after mid 2018.)  Initial Raspberry Pi support was introduced in NetBSD 6.0.  NetBSD 7.0 added complete support for the board, along with introducing support for the quad-core Raspberry Pi 2 board.  Raspberry Pi 3 support was added for NetBSD 8.  NetBSD 9 supports aarch64, meaning using the newer processors in 64-bit mode.
   
 [[images/raspberrypi.jpg]]  [[images/raspberrypi.jpg]]
   
Line 10  Initial, limited, Raspberry Pi support w Line 10  Initial, limited, Raspberry Pi support w
   
 <small>([Raspberry Pi image](http://www.flickr.com/photos/42325803@N07/8118758647/) by Christopher Lee used under CC-By-2.0 license)</small>  <small>([Raspberry Pi image](http://www.flickr.com/photos/42325803@N07/8118758647/) by Christopher Lee used under CC-By-2.0 license)</small>
   
 # What works (and what doesn't yet)  # What works
   
 ## NetBSD 7 and NetBSD 8  ## NetBSD 8
   
  - RPI1, RPI2, RPI2-1.2, RPI3, RPI3+ (except RPI3 builtin WiFi and bluetooth)   - RPI1, RPI2, RPI2-1.2, RPI3, RPI3+ (except RPI3 builtin WiFi and bluetooth)
  - RPI0 and RPI0W are expected to work (without WiFi, and one needs fdt files \todo where from?)   - RPI0 and RPI0W are expected to work (without WiFi, and one needs fdt files \todo where from?)
Line 23  Initial, limited, Raspberry Pi support w Line 23  Initial, limited, Raspberry Pi support w
  - X11 via HDMI   - X11 via HDMI
  - GPU (VCHIQ) - 3D and video decode. man page missing.   - GPU (VCHIQ) - 3D and video decode. man page missing.
  - USB host controller - dwctwo(4) and most devices work   - USB host controller - dwctwo(4) and most devices work
  - USB Ethernet - usmsc(4)   - Ethernet - usmsc(4), mue(4)
  - DMA controller driver and sdhc(4) support   - DMA controller driver and sdhc(4) support
  - RNG   - RNG
  - Audio: works. man page missing.   - Audio: works. man page missing.
Line 31  Initial, limited, Raspberry Pi support w Line 31  Initial, limited, Raspberry Pi support w
  - I²C: works, could use enhancements, man page   - I²C: works, could use enhancements, man page
  - SPI: could use enhancements, man page   - SPI: could use enhancements, man page
   
   ## NetBSD 9
   
    - aarch64 support (RPI3, and should work on all supported systems with 64-bit CPUs)
    - RPI3 new SD host controller driver
   
 ## NetBSD current  ## NetBSD current
   
  - RPI3B+    - RPI4 (using EDK2 UEFI firmware)
           - RPI4 Ethernet (Broadcom GENETv5) - genet(4)
    - RPI3/RPI4 audio with aarch64 kernels
           - Previously the driver was only included with 32-bit (ARMv7/ARMv6)
             kernels and images due to the Broadcom code having 64-bit cleanliness
             issues.
  - RPI3 builtin bluetooth   - RPI3 builtin bluetooth
  - RPI3 new SD host controller driver   - RPI3 and RPI0W builtin WiFi - bwfm(4)
    - Big endian support
   
 ## What needs documenting if it works  ## What needs documenting if it works
   
Line 46  Initial, limited, Raspberry Pi support w Line 57  Initial, limited, Raspberry Pi support w
 ## What needs work  ## What needs work
   
  - USB (host); isochronous transfers.   - USB (host); isochronous transfers.
  - RPI3 builtin WiFi   - RPI0W Bluetooth Low Energy (probably)
    - DRM/KMS
   
 # CPU types  # CPU types
   
  - RPI1 uses "earmv6hf".   - RPI1 uses "earmv6hf".
  - RPI0 uses "\todo".   - RPI0 uses "earmv6hf".
    - RPI0W uses "earmv6hf".
  - RPI2 uses "earmv7hf".   - RPI2 uses "earmv7hf".
  - RPI3 uses "earmv7hf".   - RPI2-1.2 uses "earmv7hf" or "aarch64" (ARMv8 CPU hardware)
  - RPI0W uses "\todo".   - RPI3 uses "earmv7hf" or "aarch64" (ARMv8 CPU hardware)
    - RPI4 uses "aarch64" (ARMv8 CPU hardware)
   
 Note that one can run a build of earmv6hf on the 2 and 3.  There will still be a kernel7, built to use the 2/3 hardware, but with the armv6 instruction set.  Note that one can run a build of earmv6hf on the 2 and 3.  There will still be a kernel7, built to use the 2/3 hardware, but with the armv6 instruction set.  In theory the code compiled for earmv7hf will be faster, but anecdotal experience is that it doesn't matter that much.  Builds of NetBSD for earlier revisions of ARM are unsupported.
   
 In theory the code compiled for earmv7hf will be faster, but anecdotal experience is that it doesn't matter that much.  # Installation
   
 While the evbarm port has "eb" variants (for big-endian mode), the RPI systems do not support eb and these variants will not work.  Systems built with older CPU architectures (earm, earmv4, earmv5) are not expected to work on RPI.  ## Using standard images
   
 See also [[NetBSD/aarch64|aarch64]] for running the RPI2-1.2 and RPI3/RPI3+ in 64-bit mode.  The simplest way is to download the appropriate SD card image from the NetBSD mirrors:
   
 # Installation  - The Raspberry Pi 1 requires the ARMv6 [rpi.img.gz](http://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-9/latest/evbarm-earmv6hf/binary/gzimg/rpi.img.gz).
   - The Raspberry Pi 2-3 can use the standard ARMv7 [armv7.img.gz](https://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-9/latest/evbarm-earmv7hf/binary/gzimg/armv7.img.gz) image.
   - The Raspberry Pi 3 can also use [arm64.img.gz](https://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-9/latest/evbarm-aarch64/binary/gzimg/arm64.img.gz).
   
 ## SD card structure  Decompress it and write it to the SD card:
   
 The Raspberry Pi looks for firmware and kernel.img on the first FAT32 MBR partition of the uSD card.  A separate kernel (kernel7.img) is used on RPI2 and RPI3.          $ gunzip armv7.img.gz
 The NetBSD kernel will then find NetBSD MBR partition and within that the root disklabel partition, and use that FFS partition as the root filesystem.          $ dd if=armv7.img of=/dev/rld0d conv=sync bs=1m progress=1
   
 A 2 GB card is the smallest workable size, and the installation image will fit.  After the first boot, the system resizes the NetBSD root partition to fill the card.  Note that swap is after /boot and before /, and not contained in the NetBSD fdisk partition.  However, if you don't try to change the partition structure, this should not cause you any trouble.  If you're not using NetBSD, your operating system's dd command's arguments may vary. On Windows, try [Rawrite32](https://www.netbsd.org/~martin/rawrite32/).
   
 Note that SD cards generally have limited write tolerance, so you may wish to disable atime updates via the noatime option, as is done by the default installation.  The Raspberry Pi 4 requires the [UEFI firmware](https://github.com/pftf/RPi4/releases). Write the UEFI firmware to the SD card, and then insert an USB drive with the standard NetBSD `arm64.img` written to it. The Pi will then boot from USB.
   
 ## Choosing a version  The Raspberry Pi 3 can also [boot NetBSD from UEFI firmware](https://washbear.neocities.org/rpi3-netbsd-uefi.html), but the installation process is currently more complicated. However, there are some advantages, so you might want to try anyway.
   
 First, decide if you want to install a formal release (7.2 or 8.0), a stable branch build (netbsd-7, netbsd-8), or NetBSD-current.  For people who don't know how to choose among those, a recent build of netbsd-8 is probably best, with 8.0 the choice for those who value being at exactly a formal release.  ## SD card structure
   
 See also "ebijun's image", below, which is NetBSD-current and includes packages.  The Raspberry Pi looks for firmware and kernel.img on the first FAT32 MBR partition of the uSD card.  A separate kernel (kernel7.img) is used on RPI2 and RPI3.
   The NetBSD kernel will then find NetBSD MBR partition and within that the root disklabel partition, and use that FFS partition as the root filesystem.
   
 ## Getting bits to install  A 2 GB card is the smallest workable size that the installation image will fit on.  After the first boot, the system resizes the NetBSD root partition to fill the card.  Note that swap is after /boot and before /, and not contained in the NetBSD fdisk partition.  However, if you don't try to change the partition structure, this should not cause you any trouble.
   
 You can either build a release yourself with build.sh, or get a release from the NetBSD HTTPS/FTP servers.  The bits from both sources should match, except for things like  timestamps, or because the sources are from slightly different points along branches.  Note that SD cards generally have limited write tolerance, so you may wish to disable atime updates via the noatime option, as is done by the default installation.
   
 ### Building yourself  ## Building yourself
   
 Getting sources and building a release with build.sh is not special for evbarm.  However, the evbarm port has a very large number of CPU types, compared to i386 and amd64 which have one each.  The standard approach is to use -m to define MACHINE and -a to define MACHINE_ARCH.  build.sh supports aliases that can be passed as a MACHINE value, but denote both MACHINE and a MACHINE_ARCH.   The third line uses an alias and is equal to the second, for RPI2/3.  Note that the aliases start with "evb" while the MACHINE_ARCH values do not, and that aliases have "-el" or "-eb", while the MACHINE_ARCH values have no suffix or "eb".  Getting sources and building a release with build.sh is not special for evbarm.  However, the evbarm port has a very large number of CPU types, compared to i386 and amd64 which have one each.  The standard approach is to use -m to define MACHINE and -a to define MACHINE_ARCH.  build.sh supports aliases that can be passed as a MACHINE value, but denote both MACHINE and a MACHINE_ARCH.   The third line uses an alias and is equal to the second, for RPI2/3.  Note that the aliases start with "evb" while the MACHINE_ARCH values do not, and that aliases have "-el" or "-eb", while the MACHINE_ARCH values have no suffix or "eb".
   
Line 95  Getting sources and building a release w Line 112  Getting sources and building a release w
   
 Consider setting RELEASEMACHINEDIR if you wish to build multiple MACHINE_ARCH values for a MACHINE; see build.sh.  Use something like "evbarm-earmv7hf", so that 1) earvm6 and earmv7 don't collide and 2) anita will recognize it as a type of evbarm.  Consider setting RELEASEMACHINEDIR if you wish to build multiple MACHINE_ARCH values for a MACHINE; see build.sh.  Use something like "evbarm-earmv7hf", so that 1) earvm6 and earmv7 don't collide and 2) anita will recognize it as a type of evbarm.
   
 ### NetBSD autobuild HTTPS/FTP servers  
   
 NetBSD provides nightly builds on [nyftp.netbsd.org](https://nyftp.netbsd.org/pub/NetBSD-daily/).  The next directory level is the branch being built (netbsd-7, netbsd-8, HEAD, and more), plus optionally things like compiler type.  It is followed by date/time, e.g. "HEAD/201811051650Z"; once a build is complete the symlink "latest" is adjusted to point to it.  The next level is "${MACHINE}-${MACHINE_ARCH}", e.g. "evbarm-earmv7hf", and multiple combinations are provided.  
   
 An example URL, arguably the standard approach for first-time NetBSD/RPI users, is https://nyftp.netbsd.org/pub/NetBSD-daily/netbsd-8/latest/evbarm-earmv7hf/binary/gzimg/  
   
 ### release layout  
   
 Once you get to the releasedir, self-built and autobuild releases have the same structure.  
   
  - The 'evbarm-earmv6hf/binary/gzimg/' directory contains an rpi.img file that will run on any of the RPI boards.  
  - The 'evbarm-earmv7hf/binary/gzimg/' directory contains an armv7.img file that uses the armv7 instruction set, and thus can run only on the RPI2 and RPI3 (and perhaps the CM3).  It also supports systems other than the RPI family.  
   
 \todo Explain why there is no armv7_inst.gz.  
   
 ## Preparing a uSD card  
   
 Once you have rpi.img.gz (or rpi_inst), put it on a uSD card using gunzip and dd, for example:  
   
  - gunzip rpi.img.gz  
  - dd if=rpi.img of=/dev/disk1  
   
 ## Console approaches  ## Console approaches
   
 The standard approach is to use a USB keyboard and an HDMI monitor for installation.  The standard approach is to use a USB keyboard and an HDMI monitor for installation.
Line 125  The standard approach is to use a USB ke Line 120  The standard approach is to use a USB ke
   
 By default the rpi.img is set to use the HDMI output.  If you wish to use a serial console, mount the FAT32 partition on another system and edit cmdline.txt and remove '"console=fb"'.  By default the rpi.img is set to use the HDMI output.  If you wish to use a serial console, mount the FAT32 partition on another system and edit cmdline.txt and remove '"console=fb"'.
   
  - Most (all?) USB-to-TTL serial adapters have wires for Tx, Rx and ground, and not RTS/CTS or other flow control lines.   Thus, your terminal program (or terminal) must be configured to not require flow control; a symptom of misconfiguration is that you see console output, but cannot type anything.  If so, adjust your serial console application's flow control settings to "none".   - Most (all?) USB-to-TTL serial adapters have wires for TX, RX and ground, and not RTS/CTS or other flow control lines.   Thus, your terminal program (or terminal) must be configured to not require flow control; a symptom of misconfiguration is that you see console output, but cannot type anything.  If so, adjust your serial console application's flow control settings to "none".   The serial port is at 115200 baud.
   
    - In Kermit, the command is "set flow none".     - In Kermit, the commands are "set flow none", "set carrier-watch off", "set baud 115200", and, often on NetBSD, "set line /dev/dtyU0".
    - In minicom, run "minicom -s" and set hardware flow control to "no".     - In minicom, run "minicom -s" and set hardware flow control to "no".
   
 ### Enabling ssh for installation without any console  ### Enabling ssh for installation without any console
Line 140  build.sh (and hence the FTP site) also c Line 135  build.sh (and hence the FTP site) also c
   
  - Connect an Ethernet cable from the RPI to a LAN with a DHCP server, and another host you can use for ssh.   - Connect an Ethernet cable from the RPI to a LAN with a DHCP server, and another host you can use for ssh.
  - Power on the RPI, and wait.  Watch the logs on the DHCP server, and find the IP address assigned to the RPI.   - Power on the RPI, and wait.  Watch the logs on the DHCP server, and find the IP address assigned to the RPI.
  - Use ssh to login to the address you found with user "sysinst", and password "netbsd".   - Use ssh to log in to the address you found with user "sysinst", and password "netbsd".
  - When installing, ensure that you enable DHCP and ssh, so that you can log in again after the system is installed.   - When installing, ensure that you enable DHCP and ssh, so that you can log in again after the system is installed.
   
 \todo Verify that the above is accurate and sufficient.  The rpi_inst.img.gz image will only work for systems that use earmv6hf kernels (so not RPI2/3).  See [this port-arm message](https://mail-index.netbsd.org/port-arm/2017/08/18/msg004374.html) for details.
   
 ## Installation via ebijun's image  ## Installation via ebijun's image
   
Line 153  is based on NetBSD-current and is built  Line 148  is based on NetBSD-current and is built 
 work on Raspberry Pi 1, 2 and 3.  This image is typically updated  work on Raspberry Pi 1, 2 and 3.  This image is typically updated
 every few weeks.  every few weeks.
   
  - [https://github.com/ebijun/NetBSD/blob/master/RPI/RPIimage/Image/README](https://github.com/ebijun/NetBSD/blob/master/RPI/RPIimage/Image/README)   - <https://github.com/ebijun/NetBSD/blob/master/RPI/RPIimage/Image/README>
   
   ## Boot Process
   
   https://www.raspberrypi.org/documentation/configuration/config-txt/boot.md
   
   ### DTBs
   
   Note that generally, a single dtb is loaded.  On NetBSD 9, the dtb
   file for the system is loaded by the bootloader (in flash).
   
   The RPI bootloader looks for a magic string in a trailer after the kernel to determine if it should use DTB support (the new normal) or something called ATAG (apparently the old way).  See [upstream commit introducing DTB trailer](https://github.com/raspberrypi/linux/commit/2367d8a42e2717d8d15a39a9085cc2909fae033a#diff-8f088aca645d10d79b594d58db4136f3e09caee077fe373bb08f02f2040900a9) for more information.
   
   ### Kernel format variants
   
   In netbsd-8, only the ELF and bin variants of RPI2 are built.  The bin version is used.
   
   In netbsd-9 releasedir/binary/kernels, the following 4 versions of GENERIC are produced.  (This might be the same in current.)
   
   #### netbsd-GENERIC.gz
   
   This is regular ELF and not used on RPI.
   
   #### netbsd-GENERIC.bin.gz
   
   It is unclear why this file exists on 9.  It seems to be like img, but without the trailer for DTB; this makes sense for 8.
   
   #### netbsd-GENERIC.img.gz
   
   On NetBSD >=9, the kernel with the .img suffix has the trailer to cause the bootloader to load DTB files.
   
   #### netbsd-GENERIC.ub.gz
   
   This is for u-boot and not used on RPI.
   
 ## Configuring 802.11  ## Configuring 802.11
   
Line 167  Note that the built-in WiFi in the RPI3  Line 195  Note that the built-in WiFi in the RPI3 
   
 The following pages have been published by NetBSD community members.  (Note that some of them are old.)  The following pages have been published by NetBSD community members.  (Note that some of them are old.)
   
  - https://www.cambus.net/netbsd-on-the-raspberry-pi/   - <https://www.cambus.net/netbsd-on-the-raspberry-pi/>
   
 # Maintaining a system  # Maintaining a system
   
   ## Booting single user
   
   \todo Describe how to boot single user via the serial console and via the fb console.
   
 ## vcgencmd  ## vcgencmd
   
 The program vcgencmd, referenced in the boot section,  can be found in pkgsrc/misc/raspberrypi-userland.  The program vcgencmd, referenced in the boot section,  can be found in pkgsrc/misc/raspberrypi-userland.
   
 ## Updating the kernel  ## Updating the kernel
   
  - Build a new kernel, e.g. using build.sh. It will tell you where the ELF version of the kernel is, e.g.   - Run uname -a to determine the name of the config of your current kernel.  For NetBSD <= 8, one ran RPI or RPI2.  For NetBSD >=9, one uses GENERIC.
    - Build a new kernel, e.g. using build.sh. Ideally, run "build.sh release" and look in releasedir/binary/kernels.  If building just a kernel, it will tell you where the ELF version of the kernel is, e.g.
          ...           ...
          Kernels built from RPI2:           Kernels built from GENERIC:
           /Users/feyrer/work/NetBSD/cvs/src-current/obj.evbarm-Darwin-XXX/sys/arch/evbarm/compile/RPI2/netbsd            /Users/feyrer/work/NetBSD/cvs/src-current/obj.evbarm-Darwin-XXX/sys/arch/evbarm/compile/GENERIC/netbsd
          ...           ...
    - There are multiple kernel formats produced by a release build, for use with different boot loader schemes..  For GENERIC:
  - Besides the "netbsd" kernel in ELF format, there is also a "netbsd.img" (for current) or "netbsd.bin" (for 7 and 8) kernel that is in a format that the Raspberry can boot.     - netbsd-GENERIC: A normal kernel in ELF format.
      - netbsd-GENERIC.img: In NetBSD >= 9, formatted for the RPI bootloader.
      - netbsd-GENERIC.bin: In NetBSD <= 8, formatted for the RPI bootloader.  In NetBSD >= 9, ??????  In NetBSD 9, this kernel WILL NOT boot.
      - netbsd-GENERIC.ub: A kernel in uboot format.
  - Depending on your hardware version, copy this either to /boot/kernel.img (First generation Pi, Pi Zero hardware) or to /boot/kernel7.img (Pi 2, Pi 3 hardware)   - Depending on your hardware version, copy this either to /boot/kernel.img (First generation Pi, Pi Zero hardware) or to /boot/kernel7.img (Pi 2, Pi 3 hardware)
  - reboot   - reboot
   
   \todo Explain if updating firmware is necessary when e.g. moving from 8 to 9, or 9 to current.
   
   ## Updating dtb files
   
   ### NetBSD 8
   
   On NetBSD 8, dtb files are not used.
   
   ### NetBSD 9
   
   Build a release.  gunzip the armv7.img, vnconfig it, and mount the MSDOS partition (e) e.g. on /mnt.  Copy the dtb files from /mnt/foo.dtb to /boot, and from /mnt/dtb/foo.dtb to /boot/dtb.
   
   It seems that some systems, including RPI, require dtb files in /boot, and some expect them in /boot/dtb.
   
   ### NetBSD current
   
   When updating, ensure that /boot is mounted and that you unpack the dtb set.
   
 ## Updating the firmware  ## Updating the firmware
   
   It is highly likely that running NetBSD from a given branch X with firmware from a branch Y < X will not go well.  It is unclear if firmware from a branch Y > X will work.  It is standard practice to use firmware from the right branch.
   
 A section below describes the process of updating NetBSD's copy of the firmware from upstream, with testing, by NetBSD developers.  This section is about updating a system's firmware from the firmware in a version of NetBSD.  A section below describes the process of updating NetBSD's copy of the firmware from upstream, with testing, by NetBSD developers.  This section is about updating a system's firmware from the firmware in a version of NetBSD.
   
 \todo Explain where the firmware is in the source tree, and if it is in the installed system image (such as /usr/mdec).  Explain how to update a system (presumably /boot) from either an installed system's new firmware files, or the source tree.  Explain any particular cautions.  (Updating the firmware is harder than it should be.)
   Build a release.  gunzip the armv7.img, vnconfig it, and mount the MSDOS partition (e) e.g. on /mnt.  Copy files from that to /boot that have changes, carefully.
   
   Relevant files include bootcode.bin, start.elf and start_cd.elf.
   
 Probably, for the RPI3B+, one needs to use -current, or use -8 with firmware from -current.  \todo Defuzz.  Compare cmdline.txt, but beware that just overwriting it will lose customizations like using the serial console instead of the framebuffer.
   
   \todo Explain where the firmware is in the source tree, and note that it is not in the installed system image (such as /usr/mdec).  Explain how to update a system (presumably /boot) from either an installed system's new firmware files, or the source tree.  Explain any particular cautions.
   
 \todo Explain if using updated firmware from one branch (e.g. netbsd-current) on a system using a different branch (e.g. netbsd-8) is safe.  Explain if pullups are done to release branches with new firmware.  \todo Explain if using updated firmware from one branch (e.g. netbsd-current) on a system using a different branch (e.g. netbsd-8) is safe.  Explain if pullups are done to release branches with new firmware.
   
Line 202  Probably, for the RPI3B+, one needs to u Line 262  Probably, for the RPI3B+, one needs to u
   
 The device boots by finding a file "bootcode.bin".   The primary location is a FAT32 partition on the uSD card, and an additional location is on a USB drive.  See the [upstream documentation on booting](https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/) and read all the subpages.  The device boots by finding a file "bootcode.bin".   The primary location is a FAT32 partition on the uSD card, and an additional location is on a USB drive.  See the [upstream documentation on booting](https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/) and read all the subpages.
   
 The standard approach is to use a uSD card, with a fdisk partition table containing a FAT32 partition marked active, and a NetBSD partition.  The NetBSD partition will then contain a disklabel, pointing to an FFS partition (a), a swap paritiion (b) and the FAT32 boot partition mounted as /boot (e).  The file /boot/cmdline.txt has a line to set the root partition.  The standard approach is to use a uSD card, with a fdisk partition table containing a FAT32 partition marked active, and a NetBSD partition.  The NetBSD partition will then contain a disklabel, pointing to an FFS partition (a), a swap partition (b) and the FAT32 boot partition mounted as /boot (e).  The file /boot/cmdline.txt has a line to set the root partition.
   
 One wrinkle in the standard approach is that the disk layout is "boot swap /", but the NetBSD fdisk partition starts at the location of /.   The / partition can hold a disklabel, while swap cannot.   It is normal to have swap after / (and thus within the fdisk partition), but the arrangement used permits growing / on first boot, for the typical case where a larger uSD is used, compared to the minimum image size.  One wrinkle in the standard approach is that the disk layout is "boot swap /", but the NetBSD fdisk partition starts at the location of /, so the swap partition is not within the NetBSD fdisk partition.  The / partition can hold a disklabel, while swap cannot.   It is normal to have swap after / (and thus within the fdisk partition), but the arrangement used permits growing / on first boot, for the typical case where a larger uSD is used, compared to the minimum image size.
   
 An alternate approach is to have the boot FAT32 partition as above, but to have the entire system including root on an external disk.  This is configured by changing root=ld0a to root=sd0a or root=dk0 (depending on disklabel/GPT).  Besides greater space, part of the point is to avoid writing to the uSD card.  An alternate approach is to have the boot FAT32 partition as above, but to have the entire system including root on an external disk.  This is configured by changing root=ld0a to root=sd0a or root=dk0 (depending on disklabel/GPT).  Besides greater space, part of the point is to avoid writing to the uSD card.
   
 A third approach, workable on the Pi 3 only, is to configure USB host booting (already enableed on the 3+; see the upstream documentation) and have the boot partition also on the external device.  In this case the external device must have an MBR because the hardware's first-stage boot does not have GPT support. In theory the [procedure to program USB host boot mode](https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/msd.md) will function on a NetBSD system because the programming is done by bootcode.bin.  A third approach, workable on the Pi 3 only, is to configure USB host booting (already enabled on the 3+; see the upstream documentation) and have the boot partition also on the external device.  In this case the external device must have an MBR because the hardware's first-stage boot does not have GPT support. In theory the [procedure to program USB host boot mode](https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/msd.md) will function on a NetBSD system because the programming is done by bootcode.bin.
 \todo Confirm that putting program_usb_boot_mode=1 in config.txt and booting works to program the OTP bit.  Confirm that one can then boot NetBSD from external USB.  \todo Confirm that putting program_usb_boot_mode=1 in config.txt and booting works to program the OTP bit.  Confirm that one can then boot NetBSD from external USB.
   
 There is no well-defined USB enumeration order, so the preferred approach if one has multiple USB mass storage devices is to use named wedges in both fstab and cmdline.txt.  There is no well-defined USB enumeration order, so the preferred approach if one has multiple USB mass storage devices is to use named wedges in both fstab and cmdline.txt.
   
   ## Split-mode aarch32/aarch64
   
   \todo Verify this, and add any necessary cautions about boot code.
   
   The aarch64 kernel can run aarch32 binaries, so one can boot an aarch64 kernel on a system with an aarch32 userland.
   
 # X11 and GPU  # X11 and GPU
   
   Video acceleration currently only works with 32-bit (ARMv7 and ARMv6) kernels due to the Broadcom code not being 64-bit clean.
   
   Since applications require specialized support for the GPU, only a few applications are normally accelerated.  NetBSD/aarch64 normally uses `llvmpipe` to provide fast parallel CPU-driven support for OpenGL, so should be faster when running normal applications.
   
   The situation should be improved, ideally by writing a DRM/KMS driver.
   
 ## Video playback  ## Video playback
 Accelerated video playback is supported in NetBSD 7 with the [OMXPlayer](http://pkgsrc.se/multimedia/omxplayer) application and through GStreamer with the [omx](http://pkgsrc.se/multimedia/gst-plugins1-omx) plugin.  
   Accelerated video playback is supported with the [OMXPlayer](http://pkgsrc.se/multimedia/omxplayer) application and through GStreamer with the [omx](http://pkgsrc.se/multimedia/gst-plugins1-omx) plugin.
   
 ## OpenGL ES  ## OpenGL ES
 Accelerated OpenGL ES is supported in NetBSD 7. The GL ES client libraries are included with the [misc/raspberrypi-userland](http://pkgsrc.se/misc/raspberrypi-userland) package.  
   Accelerated OpenGL ES is supported.  The GL ES client libraries are included with the [misc/raspberrypi-userland](http://pkgsrc.se/misc/raspberrypi-userland) package.
   
 ## Quake 3  ## Quake 3
   
 A Raspberry Pi optimized build of *ioquake3* is available in the [games/ioquake3-raspberrypi](http://pkgsrc.se/games/ioquake3-raspberrypi) package. To use it, the following additional resources are required:  A Raspberry Pi optimized build of *ioquake3* is available in the [games/ioquake3-raspberrypi](http://pkgsrc.se/games/ioquake3-raspberrypi) package. To use it, the following additional resources are required:
   
  - pak0.pk3 from Quake 3 CD   - pak0.pk3 from Quake 3 CD
Line 231  A Raspberry Pi optimized build of *ioqua Line 306  A Raspberry Pi optimized build of *ioqua
 Place the pak0.pk3 file in the /usr/pkg/lib/ioquake3/baseq3 directory.  Place the pak0.pk3 file in the /usr/pkg/lib/ioquake3/baseq3 directory.
   
 ## RetroArch / Libretro  ## RetroArch / Libretro
   
 Using [emulators/retroarch](http://pkgsrc.se/emulators/retroarch) it is possible to run many emulators at full speed the Raspberry Pi. Emulator cores for various gaming consoles are available in the [emulators/libretro-*](http://pkgsrc.se/search.php?so=libretro-) packages. To begin using retroarch:  Using [emulators/retroarch](http://pkgsrc.se/emulators/retroarch) it is possible to run many emulators at full speed the Raspberry Pi. Emulator cores for various gaming consoles are available in the [emulators/libretro-*](http://pkgsrc.se/search.php?so=libretro-) packages. To begin using retroarch:
   
  - Install [emulators/retroarch](http://pkgsrc.se/emulators/retroarch)   - Install [emulators/retroarch](http://pkgsrc.se/emulators/retroarch)
  - Install the libretro core for the system you would like to emulate (lets take [emulators/libretro-gambatte](http://pkgsrc.se/emulators/libretro-gambatte), a GameBoy Color emulator, as an example).   - Install the libretro core for the system you would like to emulate (lets take [emulators/libretro-gambatte](http://pkgsrc.se/emulators/libretro-gambatte), a GameBoy Color emulator, as an example).
  - Plug in a USB HID compatible Gamepad, such as the Logitech F710 in "DirectInput" mode (set "D/X" switch to "D").   - Make sure your user has read and write permissions on `/dev/vchiq`.
  - Create a config file for your gamepad using *retroarch-joyconfig*.   - Plug in a USB HID compatible Gamepad, such as the Logitech F710 in "DirectInput" mode (set "D/X" switch to "D"). Note that since the framebuffer GL driver will not allow for keyboard input in RetroArch, you will have to copy your joypad configuration from another system.
 [[!template  id=programlisting text="""   - Configure retroarch by editing $HOME/.config/retroarch/retroarch.cfg:
 $ retroarch-joyconfig -o gamepad.cfg          video_driver = "gl"
 """]]          input_driver = "null"
  - Launch the emulator from the command-line (no X required):          joypad_driver = "sdl2"
 [[!template  id=programlisting text="""          menu_driver = "rgui"
 $ retroarch --appendconfig gamepad.cfg -L /usr/pkg/lib/libretro/gambatte_libretro.so game.gbc  
 """]]  
   
 # Developer notes  # Developer notes
   
Line 269  Tests should be run on all of `rpi[0123] Line 343  Tests should be run on all of `rpi[0123]
   
 ## Testing with anita and qemu  ## Testing with anita and qemu
   
 anita has support for evbarm.  Install qemu and dtb-arm-vexpress from pkgsrc.  Note that the release subdirectory should be evbarm-earmv6hf or evbarm-earmv7hf.  See the anita section in the evbarm page.
   
   It is not currently known how to emulate a RPI in qemu, and therefore anita does not yet have support for this.  \todo Add a command-line example to run qemu emulating some RPI model.
   
   # Misc notes
   
   Miscellaneous notes about Raspberry PI.
   
   ## Power supply needed (or: why there is a little rainbow square in the top-right corner?)
   
   Raspberry Pi devices are powered by 5V micro USB and a 2.5A (2500mA)
   power supply is recommended.  For more information please read:
   
    <https://www.raspberrypi.org/documentation/faqs/#pi-power>
   
   Power glitches can also manifest in other ways, e.g. with an USB
   disk plugged:
   
   [[!template id=programlisting text="""
   sd0(umass0:0:0:0): generic HBA error
   sd0: cache synchronization failed
   """]]
   
   Using a recommended power supply avoid such issues.
   
   ## Xenon death flash (Raspberry Pi 2 is camera-shy)
   
   When using laser pointers or xenon flashes in cameras (or other
   flashes of high-intensity long-wave light) against a Raspberry Pi
   2 the Pi can power itself off.
   For more information please read:
   
 \todo Explain how to select various RPI models to emulate.   <https://www.raspberrypi.org/blog/xenon-death-flash-a-free-physics-lesson/>
 \todo Explain about how DTB works.  
 \todo Give a command line example to run qemu (without anita).  

Removed from v.1.103  
changed lines
  Added in v.1.143


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