Kernel 5.15.70 with simplefb

A very interesting discovery was made. Easy 4.4 was released with Limine 3.25, and Reynaldo reported got a black screen at bootup:

https://forum.puppylinux.com/viewtopic.php?t=6881

I recalled a change that was made last year:

https://bkhome.org/news/202111/kernel-51078-with-legacy-framebuffers.html

...I did decide to keep the legacy framebuffers, using the rather vague logic that it might be better for older hardware. At least, I think that was my reasoning at the time.

Limine developer mintsuki fixed it. But, tested with an older kernel that has "simple framebuffer" not legacy-framebuffers, and the problem I had with black screen on my old "HP motherboard" PC, just went away -- it booted.

So, it is looking like simplefb is the way to go, and I have compiled the 5.15.70 kernel, with the entries in bold enabled (builtin):

> Device Drivers > Graphics support > Frame buffer Devices > Support for frame buffer devices ── 
  ┌──────────────────────────── Support for frame buffer devices ─────────────────────────────┐   
  │  Arrow keys navigate the menu.  <Enter> selects submenus ---> (or empty submenus ----).   │   
  │  Highlighted letters are hotkeys.  Pressing <Y> includes, <N> excludes, <M> modularizes   │   
  │  features.  Press <Esc><Esc> to exit, <?> for Help, </> for Search.  Legend: [*] built-in │   
  │  [ ] excluded  <M> module  < > module capable                                             │   
  │ ┌────────^(-)───────────────────────────────────────────────────────────────────────────┐ │   
  │ │        <M>   VIA VT8623 support                                                       │ │   
  │ │        <M>   Trident/CyberXXX/CyberBlade support                                      │ │   
  │ │        <M>   ARK 2000PV support                                                       │ │   
  │ │        <M>   Permedia3 support                                                        │ │   
  │ │        <M>   Fujitsu carmine frame buffer support                                     │ │   
  │ │                DRAM timing (Eval board timings)  --->                                 │ │   
  │ │        <M>   Silicon Motion SM501 framebuffer support                                 │ │   
  │ │        <M>   SMSC UFX6000/7000 USB Framebuffer support                                │ │   
  │ │        <M>   Displaylink USB Framebuffer support                                      │ │   
  │ │        < >   Framebuffer support for IBM GXT4000P/4500P/6000P/6500P adaptors          │ │   
  │ │        < >   Virtual Frame Buffer support (ONLY FOR TESTING!)                         │ │   
  │ │        <M>   E-Ink Metronome/8track controller support                                │ │   
  │ │        <M>   Fujitsu MB862xx GDC support                                              │ │   
  │ │                GDC variant (Carmine/Coral-P(A) GDC)  --->                             │ │   
  │ │        [*]     Support I2C bus on MB862XX GDC                                         │ │   
  │ │        < >   Simple framebuffer support   CONFIG_FB_SIMPLE                            │ │   
  │ │        < >   Solomon SSD1307 framebuffer support 

Also:

> Device Drivers > Firmware Drivers ──────────────────────────────────────────────────────────── 
  ┌──────────────────────────────────── Firmware Drivers ─────────────────────────────────────┐   
  │  Arrow keys navigate the menu.  <Enter> selects submenus ---> (or empty submenus ----).   │   
  │  Highlighted letters are hotkeys.  Pressing <Y> includes, <N> excludes, <M> modularizes   │   
  │  features.  Press <Esc><Esc> to exit, <?> for Help, </> for Search.  Legend: [*] built-in │   
  │  [ ] excluded  <M> module  < > module capable                                             │   
  │ ┌───────────────────────────────────────────────────────────────────────────────────────┐ │   
  │ │            ARM System Control and Management Interface Protocol  ----                 │ │   
  │ │        < > BIOS Enhanced Disk Drive calls determine boot disk                         │ │   
  │ │        [*] Export DMI identification via sysfs to userspace                           │ │   
  │ │        < > DMI table support in sysfs                                                 │ │   
  │ │        < > iSCSI Boot Firmware Table Attributes module                                │ │   
  │ │        < > QEMU fw_cfg device support in sysfs                                        │ │   
  │ │        [ ] Mark VGA/VBE/EFI FB as generic system framebuffer  CONFIG_SYSFB_SIMPLEFB   │ │   
  │ │        [ ] Google Firmware Drivers  ----                                              │ │   
  │ │            EFI (Extensible Firmware Interface) Support  --->                          │ │   
  │ │        [ ] Load custom ACPI SSDT overlay from an EFI variable                         │ │   
  │ │            Tegra firmware driver  ----                                                │ │ 

That CONFIG_SYSFB_SIMPLEFB is named CONFIG_X86_SYSFB in the 5.10.x kernel.

Note, CONFIG_FB_SIMPLE is also deprecated, it is missing in the 5.16 kernel, replaced with CONFIG_DRM_SIMPLEDRM. Will cross that bridge when I get to it.      

Tags: easy