Kernel Requirements and Configuration¶
The Linux kernel version and configuration is critical for BC-250 stability and performance.
Kernel Version Compatibility¶
Recommended Kernels¶
Best Compatibility: - 6.15.7 - 6.17.7 - Full BC-250 support, best performance - 6.16.x - All versions work well
Stable Fallback: - 6.12.x LTS - Older but reliable - 6.13.x - Stable - 6.14.x LTS - Well-tested
Confirmed Working Versions: - 6.16.5 (Fedora 42/43) - 6.15.11-1-lts (Arch Linux) - 6.17.4 (CachyOS)
Current Recommendation
Use kernels 6.15.7 through 6.17.7 for the best BC-250 experience. Kernel support was significantly improved starting with 6.15.7.
Broken Kernels¶
Avoid These Kernel Versions
- 6.15.0 - 6.15.6: GPU initialization fails
- 6.17.8 and newer: GPU driver broken again
These versions cause:
- Kernel panics on boot
- GPU fails to initialize
- amdgpu: Failed to get gpu_info firmware error
- Black screen after boot
Known Error Messages:
[drm:amdgpu_discovery_init [amdgpu]] *ERROR* amdgpu_discovery_init failed
amdgpu 0000:01:00.0: amdgpu: Fatal error during GPU init
Required Kernel Parameters¶
Basic Parameters (All Installations)¶
Add these to GRUB configuration:
# Edit GRUB
sudo nano /etc/default/grub
# Add to GRUB_CMDLINE_LINUX_DEFAULT:
GRUB_CMDLINE_LINUX_DEFAULT="quiet amdgpu.sg_display=0"
Parameter Explanations:
quiet- Reduces boot messages (optional)amdgpu.sg_display=0- Required for kernels < 6.10 - disables scatter-gather display
amdgpu.sg_display
This parameter is only needed for kernels older than 6.10. If using 6.11+, it doesn't hurt to leave it, but it's not strictly necessary.
Performance Parameters (Optional)¶
# For maximum gaming performance
GRUB_CMDLINE_LINUX_DEFAULT="quiet amdgpu.sg_display=0 mitigations=off"
Performance Impact of mitigations=off:
- +18 FPS in Cyberpunk 2077 (60 → 78 FPS at 1080p high settings)
- Reduces CPU overhead from Spectre/Meltdown mitigations
- Security trade-off: Disables CPU vulnerability mitigations
Security vs Performance
mitigations=off improves performance but reduces security. Only use on gaming-only systems, not for systems handling sensitive data.
Memory Allocation Parameters (Advanced)¶
For maximum GPU memory access (14.5-14.75GB):
Do NOT Enable IOMMU
NEVER use amd_iommu=on - IOMMU is broken on BC-250 and causes crashes and display failures. The memory parameters above work WITHOUT enabling IOMMU.
Purpose: - Allows GPU to access more system RAM - Useful for VRAM-heavy workloads - Alternative to increasing BIOS VRAM allocation
Via modprobe (alternative method):
# Create /etc/modprobe.d/increase_amd_memory.conf
sudo nano /etc/modprobe.d/increase_amd_memory.conf
# Add:
options ttm pages_limit=3776000 page_pool_size=3776000
options amdgpu gttsize=14750
# Rebuild initramfs
sudo dracut --regenerate-all --force # Fedora
sudo mkinitcpio -P # Arch
Installation Parameter (Temporary)¶
nomodeset - Use during installation only:
Purpose: Disables GPU driver, allows booting with basic graphics
Remove After Installation
After installing Mesa drivers, remove nomodeset from GRUB. Leaving it prevents GPU acceleration.
Applying Kernel Parameters¶
Fedora/RHEL¶
# Edit GRUB config
sudo nano /etc/default/grub
# Update GRUB
sudo grub2-mkconfig -o /boot/grub2/grub.cfg
# Reboot
sudo reboot
Debian/Ubuntu¶
Arch Linux¶
# Edit GRUB config
sudo nano /etc/default/grub
# Update GRUB
sudo grub-mkconfig -o /boot/grub/grub.cfg
# Reboot
sudo reboot
Temporary Boot Parameters¶
To test parameters without permanently changing configuration:
- Reboot system
- At GRUB menu, press e to edit boot entry
- Find line starting with
linuxorlinuxefi - Add parameters to end of line
- Press Ctrl+X to boot with modified parameters
Kernel Management¶
Checking Current Kernel¶
Installing Specific Kernel Version¶
Fedora:
# List available kernels
dnf list kernel --showduplicates
# Install specific version
sudo dnf install kernel-6.14.4-104
# Set as default in GRUB if needed
sudo grub2-set-default "Fedora Linux (6.14.4-104)"
Arch Linux:
Holding Kernel Version¶
To prevent automatic updates to problematic kernel versions:
Fedora:
# Install versionlock plugin
sudo dnf install python3-dnf-plugin-versionlock
# Lock kernel at current version
sudo dnf versionlock add kernel
# List locked packages
sudo dnf versionlock list
# Remove lock
sudo dnf versionlock delete kernel
Arch Linux:
# Edit pacman.conf
sudo nano /etc/pacman.conf
# Add under [options]:
IgnorePkg = linux
# Save and exit
Debian:
# Hold kernel package
sudo apt-mark hold linux-image-6.14.11-amd64
# Unhold
sudo apt-mark unhold linux-image-6.14.11-amd64
Removing Broken Kernel¶
If kernel 6.15.0-6.15.6 or 6.17.8+ was installed and causes issues:
Fedora:
# Boot into working kernel from GRUB menu
# Remove broken kernel (example: 6.17.8)
sudo dnf remove kernel-6.17.8\*
# Or remove all 6.17.8+ kernels
sudo dnf remove 'kernel-6.17.[8-9]*' 'kernel-6.17.1[0-9]*'
# Verify removal
dnf list installed kernel
Arch Linux:
# Boot into working kernel
# Remove problematic kernel
sudo pacman -R linux # if on broken version
# Install known-good kernel
sudo pacman -S linux-lts # 6.12 or 6.14 LTS
# or
sudo pacman -S linux # check version is 6.15.7-6.17.7
Kernel Patches for BC-250¶
GPU Frequency Range Patch¶
Purpose: Enables extended frequency range (350 MHz - 2230 MHz) instead of default (1000-2000 MHz)
Distributions with Patch Included: - Bazzite (pre-applied) - PikaOS (pre-applied)
Manual Patching:
Required for: - Fedora - Arch Linux - Debian - Other distributions
Patch Application (Advanced):
- Download BC-250 frequency patch
- Apply to kernel source
- Compile custom kernel
- Install and boot
[Detailed patching guide available in community resources]
Alternative: Use distributions with patch pre-applied (Bazzite, PikaOS)
TKG Kernel (Arch-based)¶
For Arch users, linux-tkg provides easy custom kernel building:
git clone https://github.com/Frogging-Family/linux-tkg
cd linux-tkg
# Create patch directory
mkdir linux612-tkg-userpatches
# Place BC-250 patch in directory
# Run installer
./install.sh install
# Select Linux 6.12 LTS during setup
Benefits: - Easy kernel customization - Includes performance optimizations - BC-250 patch integration
Compilation Time: - Full compile: ~45 minutes - With modprobed-db: ~8 minutes
Kernel Troubleshooting¶
GPU Not Detected After Kernel Update¶
Symptoms:
- Black screen after boot
- lspci | grep VGA shows device but driver not loading
- dmesg | grep amdgpu shows errors
Solution: 1. Boot into older kernel from GRUB (hold Shift at boot) 2. Remove newer kernel 3. Hold kernel version 4. Report issue to distribution
System Boots But No GPU Acceleration¶
Check:
# Is amdgpu module loaded?
lsmod | grep amdgpu
# Check for errors
dmesg | grep -i amdgpu
# Verify rendering
glxinfo | grep "OpenGL renderer"
# Should NOT show "llvmpipe"
Possible Causes:
- nomodeset still in GRUB config
- Missing kernel parameters
- Mesa not installed
Kernel Panic on Boot¶
Symptoms: - System crashes during boot - Kernel panic message
Most Common Cause: Kernel 6.15.0-6.15.6 or 6.17.8+
Solution: 1. Boot into working kernel (hold Shift, select previous kernel) 2. Remove problematic kernel version 3. Lock kernel version to prevent auto-update
Kernel Version Matrix¶
| Kernel Version | Status | Notes |
|---|---|---|
| 6.10.x | ⚠️ Works | amdgpu.sg_display=0 required |
| 6.11.x | ✅ Good | Mesa 25.1+ required |
| 6.12.x LTS | ✅ Good | Stable fallback |
| 6.13.x | ✅ Good | Stable |
| 6.14.x LTS | ✅ Good | Well-tested |
| 6.15.0-6.15.6 | ❌ Broken | GPU init fails |
| 6.15.7-6.15.x | ✅ Recommended | Kernel support fixed |
| 6.16.x | ✅ Recommended | Full compatibility |
| 6.17.0-6.17.7 | ✅ Recommended | Best support |
| 6.17.8+ | ❌ Broken | GPU driver broken again |