Some recovery and initial-provisioning flows need a standard host protocol before usable firmware is available in persistent storage. U-Boot already provides fastboot, but the implementation can currently be started only from the U-Boot-proper command line.
This series makes USB fastboot available as an opt-in SPL service, including MMC partition flashing and Android sparse images. The interface is kept deliberately narrower in SPL: it does not support the boot command or filesystem probing, and reboot support remains platform-dependent. The first four patches separate the generic preparation from SPL enablement. They factor out the USB session runner, route USB reboot through the common handler, make shared fastboot configuration phase-aware, and add phase-aware sparse-image support. The final patch then contains the SPL-specific Kconfig, gadget behavior, documentation, and sandbox_spl build coverage. Boards which leave SPL_FASTBOOT disabled add no fastboot code or supporting library to SPL. The sandbox_spl defconfig enables the core service so that the SPL build remains covered by CI. --- Changes in v5: - Preserve the command-line USB diagnostics and document teardown behavior. - Finish converting shared fastboot configuration checks for build phases. - Require reclaiming malloc for SPL sparse writes and use a 64 KiB fill buffer. - Make environment-backed fastboot features optional in SPL. - Document SPL command, buffer, allocator, printf and reset requirements. - Build the core SPL fastboot service with sandbox_spl for CI coverage. - Link to v4: https://patch.msgid.link/20260820-ccaione-upstream-spl-fastboot-v4-0-57e5ef71c...@baylibre.com Changes in v4: - Drop RFC status. - Make the USB fastboot helper and gadget build rules phase-aware. - Use a separate command table for the SPL-supported command subset. - Document the commands available in SPL. - Apply the requested Makefile, annotation and preprocessor cleanups. - Link to v3: https://patch.msgid.link/20260731-ccaione-upstream-spl-fastboot-v3-0-dbea3ff45...@baylibre.com Changes in v3: - Rename the USB session helper to fastboot_usb_run(). - Initialize UDP and TCP sessions in their transport helpers. - Remove a redundant USB session return assignment. - Collect the Reviewed-by tag. - Link to v2: https://patch.msgid.link/20260722-ccaione-upstream-spl-fastboot-v2-0-2ba3f71c4...@baylibre.com Changes in v2: - Split the common USB session runner into a prerequisite patch. - Route USB reboot through the common fastboot handler separately. - Split phase-aware fastboot configuration and build rules. - Split phase-aware Android sparse-image support. - Keep SPL-specific behavior in the final patch. - No functional change from v1. - Link to v1: https://patch.msgid.link/20260719-ccaione-upstream-spl-fastboot-v1-1-c9bab5b0b...@baylibre.com --- Carlo Caione (5): fastboot: factor out the USB session runner fastboot: use the common handler for USB reboot fastboot: make shared configuration checks phase-aware image: sparse: add phase-aware SPL support fastboot: add SPL support cmd/fastboot.c | 53 ++------------------ configs/sandbox_spl_defconfig | 4 ++ doc/android/fastboot.rst | 48 +++++++++++++++++++ drivers/Makefile | 2 +- drivers/fastboot/Kconfig | 104 ++++++++++++++++++++++++++++++++++++++-- drivers/fastboot/Makefile | 9 ++-- drivers/fastboot/fb_block.c | 11 +++-- drivers/fastboot/fb_command.c | 99 ++++++++++++++++++++++++++++++-------- drivers/fastboot/fb_common.c | 36 ++++++++++---- drivers/fastboot/fb_getvar.c | 30 +++++++----- drivers/fastboot/fb_mmc.c | 49 +++++++++++-------- drivers/fastboot/fb_nand.c | 2 +- drivers/fastboot/fb_usb.c | 69 ++++++++++++++++++++++++++ drivers/usb/gadget/Makefile | 2 +- drivers/usb/gadget/f_fastboot.c | 9 ++-- include/fastboot.h | 10 ++++ lib/Kconfig | 13 +++++ lib/Makefile | 3 +- lib/image-sparse.c | 2 +- 19 files changed, 425 insertions(+), 130 deletions(-) --- base-commit: 527115ef6783cec49e5610c523c124b399011361 change-id: 20260718-ccaione-upstream-spl-fastboot-14fa2b6b2b64 Best regards, -- Carlo Caione <[email protected]>
