On Thu, 29 Jul 2021 at 22:41, Pintu Agarwal <pintu.ping@xxxxxxxxx> wrote: > > On Thu, 29 Jul 2021 at 17:33, Ezequiel Garcia > <ezequiel@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > On Thu, 29 Jul 2021 at 08:45, Richard Weinberger <richard@xxxxxx> wrote: > > > > > > Ezequiel, > > > > > > ----- Ursprüngliche Mail ----- > > > > [snip] > > > > > > > > Ouch, so surprised that after all these years someone is doing squashfs/mtdblock > > > > instead of using ubiblock :-) > > > > > > > > Can we patch either Kconfig or add some warn_once on mtdblock > > > > usage, suggesting to use ubiblock instead? > > > > > > a hint in Kconfig makes IMHO sense. Do you want to send a patch? > > > A warning is too much since on some tiny embedded system with NOR flash mtdblock is still > > > a good choice. > > > ubiblock is mostly useful for NAND flash. > > > > > > > I remember there was still some use case(s) for mtdblock but I can't remember > > > > now what was it, perhaps we should document the expectations? > > > > (Is that for JFFS2 to mount?) > > > > > > a long time ago mount didn't accept character devices, so you had to pass mtdblockX to mount > > > JFFS2. > > > This limitation is gone. > > > Hi, Just a further follow-up on this discussion. Whether to use /dev/mtdblock or /dev/ubiblock for rootfs (squashfs) mounting during boot. As suggested here: Instead of using this in kernel command line: [ 0.000000] Kernel command line: ... rootfstype=squashfs root=/dev/mtdblock44 ubi.mtd=40,0,30 ... I used this: [ 0.000000] Kernel command line: ... rootfstype=squashfs ubi.mtd=40,0,30 ubi.block=0,0 root=/dev/ubiblock0_0 ... The device is booting fine with ubiblock as well. But, per say, I could not find any visible difference. I just observed a slight improvement in boot time, but I need to double-check on this, with few more reboot cycles. Apart from this what are the other visible benefits of using ubiblock which can be explained to be management or internal team ? I could not find any documentation explaining the difference, except this one: http://www.linux-mtd.infradead.org/doc/ubi.html#L_ubiblock Can someone also point me to the respective driver code in case of using /dev/mtdblock and /dev/ubiblock ? Apart from theory I also want to check the impact at the code level.. Thanks, Pintu
