mdio-tools

The latest release is always available from GitHub at

https://github.com/wkz/mdio-tools/releases

Table of Contents

• Introduction
• Usage
• Build

Introduction

mdio is a low-level Linux debug tool for communicating with devices attached an MDIO bus. It improves on existing tools in this space in a few important ways:

• MDIO buses are directly addressable. Previous solutions relied on at least one Ethernet PHY on the bus being attached to a net device, which is typically not the case when the device is an Ethernet switch for example.
• Complex operations can be performed atomically. The old API only supported a single read or write of a single register. mdio sends byte code to the mdio-netlink kernel module that can perform multiple operations, store intermediate values, loop etc. As a result, things like read/mask/write operations and accesses to paged PHYs can be performed safely.

Usage

    mdio            -- List available buses
    mdio BUS        -- Probe BUS for active devices
    mdio BUS OBJ    -- Show status of OBJ
    mdio BUS OBJ OP -- Perform OP on OBJ

Options:
  -h   This help text
  -v   Show verision and contact information

Bus names may be abbreviated using glob(3) syntax, i.e. "fixed*"
would typically match against "fixed-0".

Objects:
  phy PHYAD
    Clause 22 (MDIO) PHY using address PHYAD.

    REG: u5

  mmd PRTAD[:DEVAD]
    Clause 45 (XMDIO) PHY using address PRTAD:DEVAD.

    REG: u16

  mva PHYAD
    Operate on Marvell Alaska (mv88e8xxx) PHY using address PHYAD.
    Register 22 is assumed to be the page register.

    REG: u8|"copper"|"fiber":u5

  mvls ID
    Operate on Marvell LinkStreet (mv88e6xxx) device attached to BUS
    using address ID. If ID is 0, single-chip addressing is used; all
    other IDs use multi-chip addressing.

    REG: u5|"global1"|"global2" u5

  xrs PHYAD
    Operate of Arrow/Flexibilis XRS700x device using address PHYAD.

    REG: u32 (Stride of 2, only even registers are valid)

Operations:
  raw REG [DATA[/MASK]]
    Raw register access. Without DATA, REG is read. An unmasked DATA will
    do a single write to REG. A masked DATA will perform a read/mask/write
    sequence.

    DATA: u16
    MASK: u16

Build

At the moment, the kernel module (which requires at least kernel version 5.2) has to be built separately. Set KDIR if building against a kernel in a non-standard location.

cd kernel/
make all && sudo make install

When building from GIT, the configure script first needs to be generated, this requires autoconf and automake to be installed. A helper script to generate configure is available:

./autogen.sh

Standard autotools incantation is then used, requires pkg-config to locate the libmnl development files.

./configure --prefix=/usr && make all && sudo make install