microsoft/uf2 resource
UF2 file format specification observed · 2026-08-28
Health v2 · maintenance only
62/100
- Activity 66
- Release rhythm 35
- Longevity 100
Flags: no_releases no_license
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.
- gap_med: n/a
- age_days: 3561
- days_rel: n/a
- days_push: 206
- n_releases_24m: 0
Adoption not part of the score
1030 stars · 194 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
The official specification and reference for UF2 (USB Flashing Format), a 512-byte-block file format developed by Microsoft for flashing microcontroller firmware over USB Mass Storage Class. The repository documents the block layout, magic numbers, flags, and family IDs, and links to implementations such as bootloaders and conversion tools.
Use cases
- flash firmware to a microcontroller by copying a file to a USB drive
- implement a bootloader that recognizes UF2 blocks over MSC
- convert a .bin or .hex firmware image to UF2 format
- understand the UF2 block layout and magic numbers before writing a parser
- add UF2 drag-and-drop flashing support to a dev board
- embed board family IDs so one bootloader handles multiple chip families
When to choose
- you are building or porting a bootloader that accepts firmware via a USB mass-storage drive
- you need the authoritative block format, flags, and family ID definitions to write or validate UF2 files
- you want drag-and-drop firmware updates on embedded hardware without installing drivers
- you are integrating with Microsoft MakeCode or PXT tooling that emits UF2 files
When to avoid
- you need a ready-made flashing application or GUI rather than a format specification
- your target device flashes over serial, SWD, or DFU rather than USB mass storage
- you expect runnable production code - the repo is primarily a spec with sample utilities, not a maintained library
- you need OTA or network firmware updates, which UF2 does not address
Facets
learning-resource · maturity stable
developer-tools embedded file-system documentation embedded-systems hardware developer-tools files embedded cross-platform uf2 bootloader firmware-flashing mass-storage-class microcontroller makecode file-format-specification
1 source
- readme: https://github.com/microsoft/uf2 · fetched 2026-08-28 · 236ceac29ea3
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| microsoft/uf2 | main | 62 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem