MX25L(4)

📦 version 12.2, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💾 MX25L — the mx25l driver, bestie edition 🎀

okay so this is the MX25L(4) man page, from the Kernel Interfaces Manual section (that's section 4, drivers, we love her). it's all about a driver for SpiFlash(tm)-compatible non-volatile storage devices. sit down, grab a snack 🍓, we're gonna get into it.

✨ NAME ✨

mx25l — driver for SpiFlash(tm) compatible non-volatile storage devices 💅

like. that's literally her. that's the whole vibe.

🌸 SYNOPSIS 🌸

so to get this driver compiled into your kernel, you drop this line into your kernel configuration file:

device mx25l

or, alternatively, if you'd rather load the driver as a module at boot time, you put this line in loader.conf(5):

mx25l_load="YES"

pick your fighter. both slay. 🫶

💖 DESCRIPTION 💖

okay so the mx25l driver provides support for the whole family of non-volatile storage devices that everyone calls SpiFlash(tm). these chips typically have part numbers starting with EN25, IS25, MX25, S25, SST25, or W25 — if you see one of those prefixes you already know what time it is. 👑

the mx25l driver reads the manufacturer and device ID data using opcode 0x9f to figure out whether the device is supported. and the way it checks — it looks the device ID up in a table of data inside the driver, which describes the attributes of each supported device, like block size, sector size, and device capacity. so smart. so organized. 💅

when a supported device is found, the mx25l driver creates a disk device and makes it accessible at /dev/flash/mx25l?. the new disk device then gets tasted by the available geom(4) modules, just like with any other disk device. no special treatment, she's just a disk now. periodt.

🔥 HARDWARE 🔥

the mx25l driver provides support for these devices, and honestly? the roster is giving range:

  • AT25DF641
  • EN25F32
  • EN25P32
  • EN25P64
  • EN25Q32
  • EN25Q64
  • GD25Q64
  • M25P32
  • M25P64
  • MX25L1606E
  • MX25LL128
  • MX25LL256
  • MX25LL32
  • MX25LL64
  • S25FL032
  • S25FL064
  • S25FL128
  • S25FL256S
  • SST25VF010A
  • SST25VF032B
  • W25Q128
  • W25Q256
  • W25Q32
  • W25Q64
  • W25Q64BV
  • W25X32
  • W25X64

twenty-seven icons. not one flop. 🌈

🧚 FDT CONFIGURATION 🧚

on an fdt(4) based system, the mx25l device is defined as a slave device subnode of the SPI bus controller node. and good news — all the properties documented in the spibus.txt bindings document can be used with the mx25l device. the most commonly-used ones are documented below. 💖

the properties you NEED (required) in the mx25l device subnode 🫶

  • compatible — must be the string "jedec,spi-nor". non-negotiable bestie.
  • reg — chip select address of device.
  • spi-max-frequency — the maximum bus frequency to use when communicating with this slave device. heads up though: the actual bus speed may be lower, depending on what the SPI bus controller hardware is capable of. she can only go as fast as she can go. 😭

the properties you CAN add (optional) 🎀

  • spi-cpha — empty property indicating the slave device requires shifted clock phase (CPHA) mode.
  • spi-cpol — empty property indicating the slave device requires inverse clock polarity (CPOL) mode.
  • spi-cs-high — empty property indicating the slave device requires chip select active high.

empty properties are such a mood ngl. present, but with nothing to say. 💅

⭐ HINTS CONFIGURATION ⭐

on a device.hints(5) based system — like MIPS, hi MIPS ily — these values are configurable for mx25l:

  • hint.mx25l.%d.at — the spibus the mx25l instance is attached to.
  • hint.mx25l.%d.clock — the maximum bus frequency to use when communicating with this device. again: actual bus speed may be lower, depending on the capabilities of the SPI bus controller hardware. same disclaimer, same energy.
  • hint.mx25l.%d.cs — the chip-select number to assert when performing I/O for this device. and ooh, spicy detail: set the high bit (1 << 31) to invert the logic level of the chip select line. 🤯
  • hint.mx25l.%d.mode — the SPI mode (0-3) to use when communicating with this device.

🦋 FILES 🦋

  • /dev/flash/mx25l? — provides read/write access to the storage device. this is the main character right here. 👑
  • /dev/flash/spi? — an alias for the /dev/mx25l? device, for backwards compatibility with older versions of the driver. she's keeping the old name alive out of respect. we love a nostalgic queen.

👀 SEE ALSO 👀

go read those next, bestie, that's the homework. 📚

💜 HISTORY 💜

the mx25l driver first appeared in FreeBSD 8.0. a legend from day one, no cap.

🌟 and that's the whole page! every option, every device, every property, every path — nothing skipped, nothing invented. iykyk. 💅✨

okay and for the cute sign-off: this page came to you courtesy of Debian, dated February 26, 2019 — that's the source and version vibes, and she's still serving. bye bestie, go mount something 🎀🦋💖

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