intel_reg_read

intel_reg_read <register_address_or_name>
intel_reg_read all

<register_address_or_name>
    The hexadecimal memory-mapped I/O (MMIO) address of the register to read (e.g., 0x70000), or a well-known symbolic name for a specific register (e.g., MI_MODE, RCS_RING_HEAD). The symbolic names are typically defined within the intel-gpu-tools source code.

all
    A special keyword argument to read and display the values of a common set of important Intel GPU registers. This provides a quick overview of critical hardware states without needing to specify individual addresses.

intel_reg_read is a specialized command line utility from the intel-gpu-tools suite. It enables direct reading of memory-mapped I/O (MMIO) registers on Intel integrated graphics processing units (GPUs). This tool is primarily used by graphics driver developers, debuggers, and advanced users for low-level diagnostics, hardware introspection, and understanding the GPU's current state. It provides a direct window into the GPU's configuration and status, allowing for granular examination of various hardware blocks, registers, and their values. This granular access is crucial for troubleshooting specific hardware issues, analyzing performance bottlenecks at a deep level, and verifying driver behavior against hardware specifications.

• Requires an Intel GPU and the intel-gpu-tools package to be installed.
• Typically requires root privileges (e.g., using sudo) to directly access the hardware registers, or appropriate CAP_SYS_RAWIO capabilities.
• Primarily a debugging and development tool; not intended for general user interaction or modification of GPU state. Misinterpretation of register values without deep hardware knowledge can be misleading and potentially diagnostic only.

intel_reg_read requires privileged access to interact directly with hardware registers. This typically means running the command as root (e.g., using sudo intel_reg_read ...). Without sufficient permissions, the command will fail with an "Operation not permitted" or similar error.

This command is not part of a standard Linux distribution's core utilities. It needs to be installed via the intel-gpu-tools package, which is usually available in distribution repositories (e.g., sudo apt install intel-gpu-tools on Debian/Ubuntu, sudo dnf install intel-gpu-tools on Fedora, sudo pacman -S intel-gpu-tools on Arch Linux).

The intel_reg_read command is a core component of the intel-gpu-tools project, which was developed to assist in the development, debugging, and testing of Intel's open-source graphics drivers for Linux. Its inception and continued usage are intrinsically tied to the ongoing evolution of these drivers, providing a critical low-level access point for diagnostics and hardware validation.

intel_gpu_top(1), intel_gpu_freq(1), intel_reg_write(1)