From 65b3a906f5ecc82119a9d9d78dc0fa0f91b6dd89 Mon Sep 17 00:00:00 2001 From: Peli de Halleux Date: Fri, 2 Dec 2016 22:39:41 -0800 Subject: [PATCH] Update README.md --- README.md | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/README.md b/README.md index eccb012..c064446 100644 --- a/README.md +++ b/README.md @@ -1,14 +1,15 @@ # USB Flashing Format (UF2) -UF2 (USB Flashing Format) is a name of a file format, that is particularly +UF2 (USB Flashing Format) is a file format that is particularly suitable for flashing devices over MSC (Mass Storage Class most commonly used -by various pendrives) The file consists of 512 byte blocks, each of which is +by various pendrives). The file consists of 512 byte blocks, each of which is self-contained and independent of others. Each 512 byte block consist of (see `uf2.h` for details): * magic numbers at the beginning and at the end * address where the data should be flashed * size of data +* block index and total number of blocks in file * data (up to 476 bytes; for SAMD it's 256 bytes so it's easy to flash in one go) Thus, it's really easy for the microcontroller to recognize a block of @@ -25,7 +26,7 @@ external flash chip, SD card etc.). These configuration values can be read from `INFO_UF2.TXT` file. Presence of this file can be tested to see if the board supports `UF2` flashing, -while contest, particularly `Board-ID` field, can be used for feature detection. +while contest, particularly `BOARD_ID` field, can be used for feature detection. The current flash contents of the board is exposed as `CURRENT.UF2` file. This file includes the bootloader address space. The last word of bootloader