[U-Boot] [PATCH 0/3] Raspberry Pi4: add support for DFU over USB

[Marek Szyprowski]

Hi All

This patchset enables support for DFU over USB protocol on Raspberry Pi4
board. The board has DWC2 UDC controller connected to the USB-C power
connector. Enabling DFU on it, make the u-boot development much more
convenient, as one no longer needs to swap SD-card between RPi4 board and
host machine to update the u-boot binary.

Patches are based on current 'master' u-boot branch. They were tested on
the 2019-07-10-raspbian-buster-lite.img sd-card image with the following
lines added to config.txt:
dtoverlay=dwc2,dr_mode=peripheral
dtparam=i2c_arm=on
dtparam=spi=on
enable_uart=1
uart_2ndstage=1
kernel=u-boot.bin

To enable DFU, one has to enter follwing command:
# dfu 0 mmc 0

During the development of this feature I've encountered a serious bug in
FAT write code. Over-writing discontiguous files always caused serious
filesystem corruption. This was especially anoying, because the system
environment is kept on FAT volume in uboot.env file, so 'saveenv'
basically corrupted the boot partiting on the second call.

I hope that my fix for FAT code will be helpful for non-RPi users too.

Best regards
Marek Szyprowski
Samsung R&D Institute Poland


Patch summary:

Marek Szyprowski (3):
  fat: write: fix broken write to fragmented files
  usb: dwc2_udc_otg: add bcm2835 SoC (Raspberry Pi4) support
  config: enable DFU over USB on Raspberry Pi4 boards

 configs/rpi_4_32b_defconfig                | 11 +++++++++++
 drivers/usb/gadget/dwc2_udc_otg.c          |  2 ++
 drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c | 12 ++++++------
 fs/fat/fat_write.c                         |  6 +++---
 include/configs/rpi.h                      | 10 ++++++++++
 5 files changed, 32 insertions(+), 9 deletions(-)

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2.17.1