On Mon, Oct 27, 2025 at 12:51 AM Sam Protsenko <[email protected]> wrote: > > When U-Boot is executed during USB boot [1,2] on E850-96 board, two > issues happen: > > 1. eMMC fails to initialize > 2. Attempt to use USB PHY driver leads to abort > > It was identified that issue #1 happens due to enalbed Flash Memory > Protector bits in MMC block registers during USB boot, and it's handled > in patch series [3]. > > Issue #2 on the other hand happens because ROM code expects the > bootloader (U-Boot) to download remaining binaries (LDFW and TZSW) over > USB using SMC calls. Before that, the access to USB blocks (USB PHY and > DWC3) is disabled, probably because corresponding TrustZone domains are > configured for access from Secure World only. > > This patch series implements downloading LDFW and TZSW firmware over USB > during USB boot, which makes it possible to use U-Boot for flashing > images to eMMC using fastboot and DFU protocols. That in turn simplifies > the U-Boot development, as one can use `dltool' [1] to run U-Boot binary > during USB boot, and update U-Boot on eMMC this way (e.g. using DFU). > It's not possible when using LittleKernel bootloader, as it expects > non-standard Samsung GPT partition, but in case of U-Boot we use the > regular one. > > Once this patch series and patch series [3] are applied it'll be > possible to use U-Boot during USB boot. The two series are independent > of each other, and can be applied in any particular order. > > [1] https://gitlab.com/LinaroLtd/e850-96/tools/dltool > [2] https://docs.u-boot.org/en/latest/board/samsung/e850-96.html > [3] > https://lore.kernel.org/u-boot/[email protected]/ > > Sam Protsenko (5): > board: samsung: e850-96: Keep public functions together > board: samsung: e850-96: Add routines for checking boot dev > board: samsung: e850-96: Split LDFW loading and init > board: samsung: e850-96: Add routine for loading images over USB > board: samsung: e850-96: Load firmwares over USB on USB boot > > board/samsung/e850-96/Makefile | 2 +- > board/samsung/e850-96/bootdev.c | 99 +++++++++++++++++++++++++++++++++ > board/samsung/e850-96/bootdev.h | 23 ++++++++ > board/samsung/e850-96/e850-96.c | 65 +++++++++++++++++----- > board/samsung/e850-96/fw.c | 75 ++++++++++++++++++------- > board/samsung/e850-96/fw.h | 10 +++- > 6 files changed, 239 insertions(+), 35 deletions(-) > create mode 100644 board/samsung/e850-96/bootdev.c > create mode 100644 board/samsung/e850-96/bootdev.h > > > base-commit: fd976ff3a233ae7c6a9f5bec790b02bbbf57bb24 > --
Oops, a minor mistake was found in this series. I'll send v2 shortly. > 2.39.5 >
