Hi Jaehoon, Jaehoon Chung wrote: > On 02/15/2012 12:31 AM, Johan RUDHOLM wrote: > > > Hi Chris, Jaehoon, > > > > Chris Ball wrote: > > > >> > >> Hi, > >> > >> On Tue, Feb 14 2012, Jaehoon Chung wrote: > >>> What kernel version is supported? up to linux-3.3? did you know? > >> > >> I think the only requirement is the command submission ioctl, so it > >> should work in every kernel from 3.0 onwards. > > > > Actually, to be able to write to the ext csd via the ioctl, "mmc: > core: check for zero length ioctl data" is also required. I think this > went into 3.3-rc1. > > Hi..Chris, Johan. > > I think that mmc extcsd read/write <device> is something wrong.. > If mmc extcsd write /dev/mmcblk0, then boot area1/2 is power-on-write- > protect. right? > And i ran mmc extcsd read /dev/mmcblk0, and i printed the > ext_csd[174](BOOT_WP_STATUS) > That's always 0x0. > > That means Boot-area1/2 is not protected. > In do_write_extcsd(), i think that check with BOOT_WP_STATUS[174] > whether protected or not. > not BOOT_WP[173]. > > How think about? I'm not sure... BOOT_WP_STATUS[174] was added in version 4.5, in 4.41 we only have BOOT_WP[173]. I guess we should read 174 if we have a 4.5 card, from the 4.5 spec: "To verify boot region protection read BOOT_WP_STATUS[174].", I guess this has been added because it's possible to lock only one boot partition in 4.5? The command works fine for my 4.41 card: # /data/mmc extcsd read /dev/block/mmcblk0 Power ro locking: possible Permanent ro locking: possible ro lock status: not locked # /data/mmc extcsd write /dev/block/mmcblk0 # /data/mmc extcsd read /dev/block/mmcblk0 Power ro locking: possible Permanent ro locking: possible ro lock status: locked until next power on Kind regards, Johan -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
