On Fri, Apr 05, 2013 at 01:53:15PM +0100, Luis Suzuki wrote: > I used dmesg to discover if my SDHC card is recognized but I see things like > sdhc0 and sdmmc0 and no one works when I do : disklabel sdhc0 or disklabel > sdmmc0.So,Is there a more common,usual device name for SDHC cards? Thanks.
Here's a brief overview of how it all fits together: sdhc(4) is the host controller driver, i.e. the driver for the chip which talks to the card via lines which are connected to the card's pins. This is the hardware part that drives the card's pins with electrical signals. sdmmc(4) sits on top of sdhc(4) and talks to the card using SD protocol commands which tell the card to perform I/O (the card contains a chip which runs firmware that understands this protocol). sdmmc(4) also fakes a scsibus for use by OpenBSD's SCSI subsystem, which in turn exposes an sd(4) disk device that users can access. You should be seeing something like this in dmesg output when you plug in a card: scsibus1 at sdmmc0: 2 targets, initiator 0 sd1 at scsibus1 targ 1 lun 0: <SD/MMC, Drive #01, > SCSI2 0/direct fixed sd1: 945MB, 512 bytes/sector, 1935360 sectors Now use 'disklabel sd1' to view the disklabel.
