Seeed Studio XIAO RP2350 doesn't boot
Port, board and/or hardware
RP2 2350
MicroPython version
MicroPython 1.24.1 ; XIAO RP2350
Reproduction
BOOTSEL XIAO RP2350 board, copy uf2 file, it reboots and never enumerates again
Expected behaviour
should enumerate REPL
Observed behaviour
doesn't enumerate
Additional Information
On Seeed Studio XIAO RP2350 page there is a note about incompatibility related to flash chip they use (found after struggling for a few hours...) and that they work with MicroPython team to solve this issue. Couldn't find any PRs or issues here so would like to ask if and when it should be fixed and what's the real issue is?
Code of Conduct
Yes, I agree
SEEED_XIAO_RP2350: Flash size configured as 4MB, board only has 2MB
Port, board and/or hardware
SEEED_XIAO_RP2350
MicroPython version
MicroPython v1.28.0-preview.175.ge154b6a8bf on 2026-02-17; Seeed XIAO RP2350 with RP2350
Reproduction
The SEEED_XIAO_RP2350 board definition appears to configure 4MB of flash, but the board only has 2MB. This causes the filesystem partition to extend beyond the physical flash boundary, risking silent data corruption due to address wrap-around.
MicroPython reports 3MB filesystem:
import rp2
f = rp2.Flash()
size = f.ioctl(4, 0) * f.ioctl(5, 0)
print(f"Flash: {size / 1024:.0f} KB")
# Flash: 3072 KB
import os
s = os.statvfs('/')
total = s[0] * s[2] / 1024
free = s[0] * s[3] / 1024
print(f"Total: {total:.1f} KB, Free: {free:.1f} KB")
# Total: 3072.0 KB, Free: 3064.0 KB
picotool info -a (in BOOTSEL mode) reports 2MB flash:
flash size: 2048K
Seeed's product page and wiki also confirm 2MB of flash:
- https://www.seeedstudio.com/Seeed-XIAO-RP2350-p-5944.html
- https://wiki.seeedstudio.com/getting-started-xiao-rp2350/#specification
Expected behaviour
rp2.Flash() and os.statvfs('/') should report sizes consistent with the 2MB physical flash. The filesystem partition should not extend beyond the flash boundary.
Expected usable filesystem: ~1MB (2MB flash minus ~320KB firmware, minus alignment/overhead), not 3MB.
Observed behaviour
rp2.Flash() reports 3072 KB (3MB) of flash available for the filesystem. os.statvfs('/') confirms a 3072 KB filesystem. Both exceed the physical 2MB flash size reported by picotool and the board specifications.
Writing files that fill more than ~700KB of the filesystem would likely cause address wrap-around, silently overwriting firmware or earlier filesystem data.
Additional Information
Full picotool info -a device Information:
Device Information
type: RP2350
revision: A2
package: QFN60
chipid: 0x20a0aaf2555c6673
flash devinfo: 0x0c00
current cpu: ARM
available cpus: ARM, RISC-V
default cpu: ARM
secure boot: 0
debug enable: 1
secure debug enable: 1
boot_random: a3fcac58:e68fafed:c6f6277e:2353da1d
boot type: bootsel
last booted partition: none
diagnostic source: slot 0
last boot diagnostics: 0x00000000
reboot param 0: 0x00000000
reboot param 1: 0x00000000
rom gitrev: 0x312e22fa
flash size: 2048K
Code of Conduct
Yes, I agree