nuttx/arch
Marco Casaroli 8c94a72657 rp23xx: Add an MTD driver over the unused QSPI flash.
The rp2350 executes in place from external QSPI flash, and a NuttX image
normally leaves most of that flash unused.  This exposes the unused region
as an MTD device so it can carry a filesystem, mirroring what the rp2040
port already provides with rp2040_flash_mtd.c.

The region is given by RP23XX_FLASH_MTD_OFFSET and RP23XX_FLASH_MTD_SIZE,
both multiples of the 4096 byte erase sector.  Initialization fails rather
than corrupting the running image if the region would overlap the NuttX
binary, checked against __flash_binary_end.

Erase and program use the bootrom flash routines.  Those stall instruction
fetch from the same flash, so they run from SRAM with interrupts disabled
and, on SMP builds, the other core parked; afterwards the QSPI interface is
returned to execute-in-place mode.  By default that restores the fast read
mode the bootrom configured at boot; RP23XX_FLASH_MTD_SAFE_XIP instead
always uses the bootrom flash_enter_cmd_xip routine, which is slower to
execute from but depends only on the documented bootrom entry point.

The driver answers BIOC_XIPBASE with the memory-mapped address of the
region, so a filesystem supporting execute in place can hand out real flash
pointers rather than copying into RAM.

The common board bringup registers the device as /dev/rpflash.

Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
2026-07-25 19:53:34 +08:00
..
arm rp23xx: Add an MTD driver over the unused QSPI flash. 2026-07-25 19:53:34 +08:00
arm64 fs/hostfs: Return ENOTTY for unsupported ioctl 2026-07-23 08:30:29 +02:00
avr arch/avr/src/avrdx/avrdx_delay: add custom up_udelay function 2026-06-12 09:55:11 -04:00
ceva arch/ceva: Replace board_app_initialize 2026-05-02 18:36:46 +08:00
dummy
hc style: fix checkpatch issues after debug.h move 2026-04-07 07:50:06 -03:00
mips arch/mips/jz4780: Add USB host and display controller drivers 2026-07-24 12:17:35 +08:00
misoc include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
or1k include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
renesas drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
risc-v fs/hostfs: Return ENOTTY for unsupported ioctl 2026-07-23 08:30:29 +02:00
sim arch/sim: Add PTY mode for simulated UART 2026-07-25 15:03:56 +08:00
sparc drivers: Fix comment typos — 'Pubic' → 'Public' across drivers and headers. 2026-07-02 13:29:48 +08:00
tricore arch/tricore: Add hardware debug breakpoint and watchpoint support. 2026-05-22 15:38:36 +08:00
x86 drivers/efuse/efuse: Drivers Registered With World Write Permissions(Part 1) 2026-07-13 12:08:01 +02:00
x86_64 !include/fcntl.h: align open flags with Linux values 2026-06-30 13:43:44 +08:00
xtensa fs/hostfs: Return ENOTTY for unsupported ioctl 2026-07-23 08:30:29 +02:00
z16 include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
z80 style: fix checkpatch issues after debug.h move 2026-04-07 07:50:06 -03:00
CMakeLists.txt arch/z80: migrate to SPDX identifier 2024-12-02 17:23:25 +08:00
Kconfig sched/clock/clock_delay: added config flag to remove weak up_udelay 2026-06-12 09:55:11 -04:00