Hi all, I've been trying to develop a device simulator for the NAND flash (in the sim).
A short note on what this does is create a virtual NAND flash (from RAM) and provide a driver, as well as a wrapper around the upper half (which for now, does nothing extra). This helps in creating records of reads/writes/erases (in a separate file) for testing and statistics purposes. Since littlefs is one of the supported filesystems on MTD devices, I tried to use it to test mount but it tries to use an ioctl with BIOC_FLUSH in the format process, which is not supported as far as code in drivers/mtd/mtd_nand.c go. *Should that be something that the NAND driver should support?* Here are the logs of that process, the first ioctl is for MTDIOC_GEOMETRY (which is supported), and second for BIOC_FLUSH (in *bold*): nuttx ➤ make && ./nuttx LD: nuttx login: admin password: User Logged-in! nsh> ls /dev /dev: console gpio0 gpio1 gpio2 gpio3 loop null oneshot ram0 ram1 ram2 zero nsh> mtddev Size: 2097152 B Pages: 4096 Blocks: 33 Writing...Done Driver running nsh> ls /dev /dev: console gpio0 gpio1 gpio2 gpio3 loop mtd null oneshot ram0 ram1 ram2 zero nsh> mount -t littlefs -o forceformat /dev/mtd /hi Upper! ioctl Command: 1537 | BIOC_FLUSH: 1293 Upper! bread Page 128 Lower! rawread : Page 128 Lower! rawread : Page 129 Lower! rawread : Page 130 Lower! rawread : Page 131 Upper! erase Lower! eraseblock : Block 0 Upper! bread Page 0 Lower! rawread : Page 0 Lower! rawread : Page 1 Lower! rawread : Page 2 Lower! rawread : Page 3 Upper! bread Page 4 Lower! rawread : Page 4 Lower! rawread : Page 5 Lower! rawread : Page 6 Lower! rawread : Page 7 Upper! bwrite Lower! rawwrite : Page 0 Lower! rawwrite : Page 1 Lower! rawwrite : Page 2 Lower! rawwrite : Page 3 Upper! ioctl *Command: 1293 | BIOC_FLUSH: 1293* Error Upper! ioctl | -25 Upper! bread Page 0 Lower! rawread : Page 0 Lower! rawread : Page 1 Lower! rawread : Page 2 Lower! rawread : Page 3 nx_mount: ERROR: Bind method failed: -28 nsh: mount: mount failed: 28 nsh> The logs with "Upper!" refer to the upper half of the driver being executed, and same for the lower, and the pages are numbered from the start of the device (ie. (block << LOG_N_BLOCKS_PER_PAGE) + page_in_block)). Regards, SP
