usb_selftest_ospi Directory Reference

Directory dependency graph for usb_selftest_ospi:

Directories
	inc
	src

Detailed Description

Brings the board's onboard Octo-SPI flash (IS25LX512M at U16) up as a USB drive and verifies it against itself on-chip – no PC in the loop. The two USB ports are cabled to each other and one image runs both USB stacks plus the xSPI flash.

At boot the device erases and programs a 1 MiB OSPI region at offset 0x100000 with a deterministic, sector-derived pattern through ra8_xspi, so the flash genuinely holds known content. USBFS (J11) exposes that region as a read-only synthesized FAT16 volume whose media-read pulls each sector straight off the flash. USBHS (J7) is the polled first-party host stack (ra8_usb_hmsc + ra8_fs), which mounts the volume, streams the data region back over raw multi-block READ(10), and checks every sector against the same pattern formula.

The host recomputes the expected pattern rather than reading the flash itself, so the single xSPI controller has exactly one user – the device class thread – and there is no contention, while the loop still proves the OSPI erase

• program + read round-trips intact over USB.

OSPI bring-up (mirrors flash_journal, #44)

ra8_board_io_expander_set_octospi_active, then ra8_board_xspi_pins_init (OCTA pins PSEL 0x1C plus a RESET pulse on the IS25LX512M, xSPI CS1), then ra8_xspi_init in 1S-1S-1S. Addressing is 0-based into the chip, and the test window at 0x100000 is clear of flash_journal's offset-0 record. Erase granularity is the 4 KiB sector.

Scope

This app exposes OSPI read-only: the host verifies content the device wrote. The narrower persistent-media write path is now covered separately by usb_selftest_ospi_rw, while usb_selftest_microsd and usb_selftest_mlun cover card readback and per-LUN addressing. A general host-formatted OSPI filesystem that survives power cycles would still need a read-modify-erase-write backing (4 KiB erase granularity against 512-byte LBAs); that general filesystem mode is outside this read-only app's contract. WRITE(10) STALL recovery is tracked by open issue #92.

Pinout

OSPI: OCTA pins (PSEL 0x1C), xSPI CS1 (IS25LX512M). FS device: P4_07 VBUS sense, P5_00 VBUSEN GPIO LOW, P8_14/P8_15 data (PSEL usb_fs). HS host: SW4-8 Host via the U15 expander, PD07 HIGH (U18 powers J7), P4_08 VBUS sense (PSEL usb_hs). Console: PD_02/PD_03 SCI8. The device advertises VID 0x1209 with a per-app PID; bench use only.