bc250-console/files/system/usr/share/bc250-40cu/vendor/bc250-cu-live-manager/README.md

BC-250 CU Live Manager

Interactive WGP and CU dispatch control for AMD BC-250 (gfx1013) using UMR.

Test factory, full, and custom WGP layouts from a terminal UI, then optionally save a chosen layout so it is restored on boot.

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What this tool does

The AMD BC-250 normally boots with a factory driver topology of 24 CUs. This tool reads that driver topology, shows it in a live dashboard, and lets you route additional WGPs through UMR at runtime.

Layout	Meaning	WGP count	CU count
Factory WGPs	WGPs enabled by the driver when AMDGPU boots	12 WGPs	24 CUs
Full dispatch	All WGPs handled by this tool are routed	20 WGPs	40 CUs
Custom table	Your manually selected WGP routing table	User selected	User selected

Each WGP contains 2 CUs. The factory layout is therefore 12 WGPs, and full dispatch is 20 WGPs.

Important

Live changes are temporary unless you save the table and install the boot service. If you only apply a live table, the driver topology is restored after reboot.

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Quick start

Download the script:

curl -L -o bc250-cu-live-manager.sh https://raw.githubusercontent.com/WinnieLV/bc250-cu-live-manager/refs/heads/main/bc250-cu-live-manager.sh
chmod +x bc250-cu-live-manager.sh

Start the interactive UI:

sudo ./bc250-cu-live-manager.sh

Running the script without a command opens the menu.

If umr is missing, the UI warns you and asks once whether it should try to install it.

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Dashboard and editor

Main dashboard

WGP table editor

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Understanding the WGP table

The table is split into four shader-engine and shader-array rows:

Row	Meaning
SE0.SH0	Shader Engine 0, Shader Array 0
SE0.SH1	Shader Engine 0, Shader Array 1
SE1.SH0	Shader Engine 1, Shader Array 0
SE1.SH1	Shader Engine 1, Shader Array 1

Each row has five WGP positions:

WGP	CU pair
WGP0	CU0-CU1
WGP1	CU2-CU3
WGP2	CU4-CU5
WGP3	CU6-CU7
WGP4	CU8-CU9

Legend

Marker	Meaning	Notes
D+	Driver topology WGP, currently routed	Factory-enabled at driver boot. These form the 24 CU layout.
S+	SPI-routed WGP only	Enabled by the live routing table, not part of the driver boot topology.
D!	Driver topology WGP, not routed	Unsafe or blocked state. The script warns and refuses unsafe live disables.
--	Off	Not currently routed.

D+ entries are the factory WGPs reported by the driver when it booted. They are the reference point for the factory 24 CU configuration.

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Menu actions

The UI is designed so that write operations are reviewable. Pressing an action key does not silently write registers. Live write actions show a safety disclaimer and an apply confirmation unless --yes is used.

Key	Menu label	Clear name	What happens
e	Edit WGP table	Custom WGP editor	Opens the WGP table editor. Toggle unlocked WGPs, then press Enter or a to review and apply the target table.
f	Full dispatch	Full 40 CU dispatch	Builds a target table where all 20 WGPs are routed. The table is written only after you accept the safety prompt and confirm the change.
t	Driver dispatch	Restore factory WGPs	Builds a target table from the driver boot topology. This returns routing to the factory 24 CU layout after confirmation.
w	Write table	Save current table	Saves the current live table to /etc/bc250-cu-live-manager.conf. This prepares it for boot restore, but does not install the service by itself.
i	Install service	Enable boot restore	Installs and enables the systemd service that reapplies the saved table on boot. It uses the table saved by Write table.
u	Uninstall service	Remove boot restore	Disables and removes the boot service and saved config.
q	Quit	Exit	Leaves the current live state as it is until reboot or until another action changes it.

Note

Full dispatch and Restore factory WGPs are live actions, but they are not applied just by pressing f or t. The script first shows the target table, then asks for confirmation. Only after confirmation are the registers updated.

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Editor controls

Key	Action
Arrow keys	Move around the table
h j k l	Move using Vim-style keys
Space	Toggle the selected unlocked WGP
Enter or a	Review and apply the selected table
q	Cancel and return to the menu

Driver-active WGPs cannot be disabled live. The editor keeps those entries locked to avoid unsafe live disable paths.

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Common workflows

Try full 40 CU dispatch until reboot

Open UI -> press f -> type accept -> review target table -> confirm y

This routes all 20 WGPs live. Nothing is saved for reboot unless you also use Write table and install the service.

Make full 40 CU dispatch survive reboot

Open UI -> press f -> type accept -> confirm y -> press w -> confirm y -> press i -> confirm y

This applies the 40 CU table, saves that live table, then installs the systemd service so the saved table is replayed on the next boot.

Restore the factory 24 CU layout

Open UI -> press t -> type accept -> review target table -> confirm y

This restores the WGP routing table to the driver boot topology, which is the factory 24 CU layout.

To keep the factory layout on future boots, either uninstall the boot service with u, or press w after restoring so the factory table becomes the saved boot table.

Build and save a custom WGP layout

Open UI -> press e -> toggle WGPs -> Enter -> type accept -> confirm y -> press w -> confirm y -> press i -> confirm y

This applies a custom table live, saves it, and enables automatic restore on boot.

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Temporary vs persistent changes

Action	Changes live table now	Survives reboot by itself	Purpose
Apply from editor	Yes, after confirmation	No	Test a custom table live
Full dispatch	Yes, after confirmation	No	Test or apply 40 CUs live
Restore factory WGPs	Yes, after confirmation	No	Return to the 24 CU driver topology live
Write table	No	Not by itself	Save the current live table to config
Install service	No	Yes, if a table is saved	Reapply the saved table at boot
Apply service	Yes, after confirmation when run manually	No	Apply the saved boot table immediately

For persistence, both steps matter:

1. Write table
2. Install service

Installing the service without a saved table does not preserve the current live state. Writing a table without the service saves the config, but nothing reapplies it automatically after reboot.

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Write-table indicator

The action menu always shows:

[w] Write table

When the saved boot table is missing or does not match the current live table, it becomes:

[w] Write table *

The * means the current live table is not saved as the boot table.

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Requirements

Hardware

• AMD BC-250
• PCI ID 13fe

Software

• bash
• umr
• python3
• libdrm_amdgpu.so.1
• systemd for boot restore
• Root privileges for register access

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Installing UMR

The built-in installer supports these package managers:

System	Package tool
Arch / CachyOS	pacman / paru
Fedora	dnf
Bazzite and immutable Fedora systems	rpm-ostree

Arch, CachyOS, Fedora

sudo ./bc250-cu-live-manager.sh install-umr
sudo ./bc250-cu-live-manager.sh

Bazzite / rpm-ostree

sudo ./bc250-cu-live-manager.sh install-umr
sudo reboot
sudo ./bc250-cu-live-manager.sh

Notes for immutable systems:

• rpm-ostree install changes the host image and requires a reboot.
• If /usr/local/bin is not writable, service installation falls back to /var/usrlocal/bin.

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Boot restore

Boot restore is optional. Use it only when you want a selected WGP table to return after reboot.

The saved config lives here:

/etc/bc250-cu-live-manager.conf

Example:

BC250_WGP_MASKS=0x1f,0x1f,0x1f,0x1f
UMR_ASIC=cyan_skillfish.gfx1013
UMR_INSTANCE=1
UMR=/usr/bin/umr

Key	Meaning
BC250_WGP_MASKS	Saved WGP masks in SE0.SH0,SE0.SH1,SE1.SH0,SE1.SH1 order
UMR_ASIC	UMR ASIC selector
UMR_INSTANCE	UMR DRI instance
UMR	Path to the UMR binary

The systemd unit loads this file as an EnvironmentFile. On boot, the service runs the saved table through apply-service using --yes, so it can restore the table without an interactive prompt.

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CLI reference

The UI is recommended, but the same operations can be scripted.

Status

sudo ./bc250-cu-live-manager.sh status

Live dispatch presets

# Enable all supported WGPs: 40 CUs after confirmation
sudo ./bc250-cu-live-manager.sh enable all

# Restore the driver boot topology: factory 24 CUs after confirmation
sudo ./bc250-cu-live-manager.sh stock-dispatch

Target a single WGP or CU pair

sudo ./bc250-cu-live-manager.sh enable-wgp 1.0.4
sudo ./bc250-cu-live-manager.sh disable-wgp 1.0.4

sudo ./bc250-cu-live-manager.sh enable-cu 1.0.8
sudo ./bc250-cu-live-manager.sh disable-cu 1.0.8

enable-cu and disable-cu still operate at WGP granularity. For example, CU 8 maps to WGP 4, which controls CU 8 and CU 9 together.

Boot restore commands

# Save the current live table
sudo ./bc250-cu-live-manager.sh write-service-table

# Install and enable boot restore
sudo ./bc250-cu-live-manager.sh install-service

# Apply the saved table now
sudo ./bc250-cu-live-manager.sh apply-service

# Remove boot restore
sudo ./bc250-cu-live-manager.sh uninstall-service

Useful flags

Flag	Use case
--yes	Skip interactive prompts for trusted automation
--dry-run	Print intended UMR writes without applying them
--force	Override the BC-250 PCI detection guard
--umr-instance <n>	Force a specific UMR DRI instance

Examples:

sudo ./bc250-cu-live-manager.sh --yes enable all
sudo ./bc250-cu-live-manager.sh --dry-run enable all
sudo ./bc250-cu-live-manager.sh --umr-instance 1 status

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What the script changes

The tool reads and writes these BC-250 dispatch-related registers through UMR:

• mmCC_GC_SHADER_ARRAY_CONFIG
• mmSPI_PG_ENABLE_STATIC_WGP_MASK
• mmRLC_PG_ALWAYS_ON_WGP_MASK

Defaults:

Setting	Value
ASIC selector	cyan_skillfish.gfx1013
Register naming	mm*

Apply operations clear the BC-250 CC harvest mask before writing SPI masks, following the known working live unlock sequence.

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Kernel patch

No kernel patch is required for this workflow.

This script writes live dispatch registers directly through UMR. Kernel patch material is still useful for research and alternate workflows, but it is not required for this tool.

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Safety behavior

• Write actions show a safety disclaimer unless --yes is used.
• Interactive dispatch actions show the current table, the target table, and the proposed WGP changes before applying.
• Type accept for the safety disclaimer, then confirm the dispatch plan with y.
• Live disable paths are blocked when they would disable driver-active WGPs.
• Driver-active WGPs are treated as locked in the editor.
• Boot persistence only happens after a table is saved and the service is installed.

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Credits and references

• Kernel patch and research base:
  https://github.com/duggasco/bc250-40cu-unlock
• Live unlock test and demo script:
  https://github.com/gennro/bc250-toolkit/blob/main/CachyOS-BC250-CU-Unlock.sh