I decided – after some time – to do some more with the Raspberry Pi 3, and set it up as a small network print server..<\/p>\n
As there was now an ‘official’ version of Fedora 27 for the Pi3, I decided to use this..\u00a0\u00a0 Details are here, and links to aarch64<\/strong> images are near the bottom of the article..\u00a0\u00a0 https:\/\/fedoraproject.org\/wiki\/Architectures\/ARM\/Raspberry_Pi<\/a><\/p>\n This version uses u-boot to load EFI, which then boots the Pi3 in the ‘traditional’ way..\u00a0\u00a0 After creating the system on the micro-sd card, I ‘saved\/restored’ the root filesystem, and modified the partition layout to make it resident on a ‘primary’ partition, rather than ‘extended’, but this was just a personal preference..<\/p>\n As I needed to use a serial console, I uncommented\u00a0 enable_uart=1<\/span><\/strong> in config.txt<\/strong>, and made the appropriate changes to the kernel boot command line..<\/p>\n As usual, the standard Fedora kernel config included many unwanted device selections and options, and so I decided to create a more Pi3-specific one..\u00a0\u00a0 A search found some possible candidates, and I tried several of these..<\/p>\n As a result, I found that the Broadcom GPU\/DRM driver caused multiple tombstones during the boot process, and killed the HDMI monitor connection:<\/p>\n So, I disabled this ( ‘Broadcom VC4 Graphics<\/strong><\/span>‘ ), and just used the framebuffer option..\u00a0\u00a0\u00a0\u00a0 The device will (obviously) be used ‘headless’, so this is not an issue..<\/p>\n It was a refreshing change to be able to use the x86-standard kernel compile\/install commands, and to be able to use grub-customizer<\/strong> to handle boot options etc..\u00a0\u00a0 I set up the dtb<\/strong><\/em> link in the \/boot<\/strong><\/span> directory to match the Fedora example..<\/p>\n I did find slightly confusing behaviour with the console options…\u00a0\u00a0 I had (temporarily) modified grub.cfg to include the usual console=tty0 console=ttyS0,115200n8<\/strong><\/span>, and this worked OK at first boot, but after I had compiled\/installed later kernels, and included this in the grub parameters, this stopped working, and there was no output on the serial\/uart connection at boot time, after the usual grub menu dialogue..<\/p>\n I then discovered that – for some reason – the ports had changed, and now required console=tty1 console=ttyS1,115200n8. <\/strong>This worked OK for the Fedora-supplied kernels, but not for the self-compiled ones..\u00a0\u00a0 I then found that the uart\/port selections in the kernel configs I was testing had been – deliberately – disabled, probably due to the fact that these console options cause performance degradation, because of design tradeoffs on the Pi3..<\/span><\/span><\/p>\n So, I modified the kernel config in the appropriate areas:<\/p>\n Select ‘Console on 8250\/16550 serial port<\/span><\/strong>‘ After this, all was well:<\/p>\n I have put a copy of the\u00a0 kernel config at https:\/\/pastebin.com\/thmebsn0<\/a><\/p>\n Robert Gadsdon.\u00a0 December 12, 2017.<\/em><\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" I decided – after some time – to do some more with the Raspberry Pi 3, and set it up as a small network print server.. As there was now an ‘official’ version of Fedora 27 for the Pi3, I decided to use this..\u00a0\u00a0 Details are here, and links to aarch64 images are near the bottom of …<\/span> Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[1132,5,10,11,14,15,16,19,21,1160],"tags":[1135,1770,1768,1173,1767,242,1766,1769,1162],"class_list":["post-2147","post","type-post","status-publish","format-standard","hentry","category-aarch64","category-compilation","category-fedora","category-hacks","category-kernel","category-linux-2","category-linux-arm","category-opinion","category-raspberry-pi","category-uefi","tag-aarch64","tag-custom-config","tag-fedora-27","tag-kernel","tag-kernel-4-14-5","tag-linux","tag-pi3","tag-uart-console","tag-uefi"],"_links":{"self":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts\/2147","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2147"}],"version-history":[{"count":3,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts\/2147\/revisions"}],"predecessor-version":[{"id":2150,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=\/wp\/v2\/posts\/2147\/revisions\/2150"}],"wp:attachment":[{"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2147"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2147"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rglinuxtech.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2147"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Fdisk:\r\nDevice Boot Start End Sectors Size Id Type<\/span><\/strong>\r\n\/dev\/mmcblk0p1 * 2048 342015 339968 166M 6 FAT16<\/span><\/strong>\r\n\/dev\/mmcblk0p2 342016 2439167 2097152 1G 83 Linux<\/span><\/strong>\r\n\/dev\/mmcblk0p3 2439168 3487743 1048576 512M 82 Linux swap \/ Solaris<\/span><\/strong>\r\n\/dev\/mmcblk0p4 3487744 125042687 121554944 58G 83 Linux\r\n............\r\n# cat \/etc\/fstab\r\n\/dev\/mmcblk0p1 \/boot\/efi vfat umask=0077,shortname=winnt 0 2\r\n\/dev\/mmcblk0p2 \/boot ext4 defaults 1 2\r\n\/dev\/mmcblk0p3 swap swap defaults 0 0\r\n\/dev\/mmcblk0p4 \/ ext4 defaults 1 1\r\n<\/span><\/strong><\/pre>\n..................<\/span><\/strong>\r\n OK ] Mounted Temporary Directory (\/tmp).<\/span><\/strong>\r\nvc4_hdmi 3f902000.hdmi: vc4-hdmi-hifi <-> 3f902000.hdmi mapping ok<\/span><\/strong>\r\nvc4-drm soc:gpu: bound 3f902000.hdmi (ops vc4_hdmi_ops [vc4])<\/span><\/strong>\r\nvc4-drm soc:gpu: bound 3f806000.vec (ops vc4_vec_ops [vc4])<\/span><\/strong>\r\nvc4-drm soc:gpu: bound 3f400000.hvs (ops vc4_hvs_ops [vc4])<\/span><\/strong>\r\nvc4-drm soc:gpu: bound 3f206000.pixelvalve (ops vc4_crtc_ops [vc4])<\/span><\/strong>\r\nvc4-drm soc:gpu: bound 3f207000.pixelvalve (ops vc4_crtc_ops [vc4])<\/span><\/strong>\r\nvc4-drm soc:gpu: bound 3f807000.pixelvalve (ops vc4_crtc_ops [vc4])<\/span><\/strong>\r\nvc4-drm soc:gpu: bound 3fc00000.v3d (ops vc4_v3d_ops [vc4])<\/span><\/strong>\r\n[drm] Initialized vc4 0.0.0 20140616 for soc:gpu on minor 0<\/span><\/strong>\r\n[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).<\/span><\/strong>\r\n[drm] Driver supports precise vblank timestamp query.<\/span><\/strong>\r\nConsole: switching to colour frame buffer device 240x67<\/span><\/strong>\r\nvc4-drm soc:gpu: fb0: frame buffer device<\/span><\/strong>\r\n[ OK ] Started udev Wait for Complete Device Initialization.<\/span><\/strong>\r\n[ OK ] Started LVM2 metadata daemon.<\/span><\/strong>\r\n[ OK ] Started Monitoring of LVM2 mirrors,\u2026sing dmeventd or progress polling.<\/span><\/strong>\r\n[ OK ] Reached target Local File Systems (Pre).<\/span><\/strong>\r\n Starting File System Check on \/dev\/mmcblk0p1...<\/span><\/strong>\r\n Starting File System Check on \/dev\/mmcblk0p2...<\/span><\/strong>\r\n[ OK ] Started File System Check on \/dev\/mmcblk0p1.<\/span><\/strong>\r\n[ OK ] Started File System Check on \/dev\/mmcblk0p2.<\/span><\/strong>\r\n Mounting \/boot...<\/span><\/strong>\r\n[CRTC:67:crtc-2] vblank wait timed out<\/span><\/strong>\r\n------------[ cut here ]------------<\/span><\/strong>\r\nWARNING: CPU: 2 PID: 21 at drm_atomic_helper_wait_for_vblanks.part.7+0x248\/0x278 [drm_kms_helper]<\/span><\/strong>\r\nModules linked in: vc4 snd_soc_core snd_pcm_dmaengine snd_seq snd_seq_device snd_pcm snd_timer snd smsc95xx drm_kms_helper usbnet cfbfillrect cfbimgblt mii cfbcopyarea drm syscopyarea sysfillrect sysimgblt fb_sys_fops uio_pdrv_genirq uio efivarfs pwm_bcm2835 i2c_bcm2835 ipv6<\/span><\/strong>\r\nCPU: 2 PID: 21 Comm: kworker\/2:0 Not tainted 4.14.5 #1<\/span><\/strong>\r\nEXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)<\/span><\/strong>\r\nHardware name: raspberrypi rpi\/rpi, BIOS 2017.09 10\/10\/2017<\/span><\/strong>\r\nWorkqueue: events output_poll_execute [drm_kms_helper]<\/span><\/strong>\r\ntask: ffffffc03c85c600 task.stack: ffffff80088c0000<\/span><\/strong>\r\nPC is at drm_atomic_helper_wait_for_vblanks.part.7+0x248\/0x278 [drm_kms_helper]<\/span><\/strong>\r\nLR is at drm_atomic_helper_wait_for_vblanks.part.7+0x248\/0x278 [drm_kms_helper]<\/span><\/strong>\r\npc : [<ffffff80007423e8>] lr : [<ffffff80007423e8>] pstate: 40000145<\/span><\/strong>\r\nsp : ffffff80088c3aa0<\/span><\/strong>\r\n................\u00a0\u00a0\u00a0\u00a0 etc... etc...<\/span><\/strong><\/pre>\n
\nChange ‘Maximum 8250\/16550 and compatible serial ports<\/span><\/strong>‘\u00a0 to ‘4<\/strong>‘<\/span><\/span>
\nChange ‘Maximum 8250\/16550 serial ports to register at runtime<\/strong><\/span>‘\u00a0 to ‘4<\/span><\/strong>‘<\/span><\/span><\/p>\n..................<\/span><\/strong>\r\n[ 0.000349] console [tty1] enabled<\/span><\/strong>\r\n.............<\/span><\/strong>\r\n[ 0.722248] 3f215040.serial: ttyS1 at MMIO 0x0 (irq = 61, base_baud = 31250000) is a 16550<\/span><\/strong>\r\n[ 1.279189] console [ttyS1] enabled<\/span><\/strong>\r\n.....................\r\nFedora 27 (Workstation Edition)\r\nKernel 4.14.5 on an aarch64 (ttyS1)\r\n...................\r\n$ uname -a\r\nLinux rgprint 4.14.5 #2 SMP PREEMPT Mon Dec 11 23:20:51 PST 2017 aarch64 aarch64 aarch64 GNU\/Linux<\/span><\/strong><\/pre>\n