[Android Development on Bada] nbates66:
i'm unsure what you're getting at here, kernel and platform correctly control basic mounting and unmounting of sdcard and external sdcard for use of the system itself ok, only problem is mass storage only mounts one of the devices.

I don't know how to check these, since that /devices/ structure isn't something that is in root folder, /dev/block/platform only shows s3c-sdhci.0 for internal sdcard and s3c-sdhci.2 for external sdcard.

log output filtered to vold when mounting usb mass storage, internal sd mounts fine but external appears as a drive with no media inserted:

01-07 18:29:51.433: D/VoldCmdListener(64): volume shared /mnt/sdcard ums
01-07 18:29:52.511: D/VoldCmdListener(64): storage users /mnt/sdcard
01-07 18:29:52.648: D/VoldCmdListener(64): asec list
01-07 18:29:52.718: D/VoldCmdListener(64): storage users /mnt/sdcard
01-07 18:29:52.898: D/VoldCmdListener(64): volume unmount /mnt/sdcard force
01-07 18:29:52.902: D/Vold(64): Volume sdcard state changing 4 (Mounted) -> 5 (Unmounting)
01-07 18:29:53.914: I/Vold(64): /mnt/secure/staging/.android_secure sucessfully unmounted
01-07 18:29:53.914: I/Vold(64): /mnt/secure/asec sucessfully unmounted
01-07 18:29:53.914: I/Vold(64): /mnt/secure/staging sucessfully unmounted
01-07 18:29:53.914: I/Vold(64): /mnt/sdcard unmounted sucessfully
01-07 18:29:53.914: D/Vold(64): Volume sdcard state changing 5 (Unmounting) -> 1 (Idle-Unmounted)
01-07 18:29:53.925: D/VoldCmdListener(64): volume share /mnt/sdcard ums
01-07 18:29:53.929: D/Vold(64): Volume sdcard state changing 1 (Idle-Unmounted) -> 7 (Shared-Unmounted)
01-07 18:29:53.980: D/VoldCmdListener(64): volume shared /mnt/sdcard ums

this is vold mounting both devices during boot, filtered to vold tag:

01-07 18:41:37.609: I/Vold(64): Vold 2.1 (the revenge) firing up
01-07 18:41:37.644: D/Vold(64): Volume sdcard state changing -1 (Initializing) -> 0 (No-Media)
01-07 18:41:37.644: D/Vold(64): Volume emmc state changing -1 (Initializing) -> 0 (No-Media)
01-07 18:41:37.699: D/Vold(64): Volume sdcard state changing 0 (No-Media) -> 2 (Pending)
01-07 18:41:37.699: D/Vold(64): Volume sdcard state changing 2 (Pending) -> 1 (Idle-Unmounted)
01-07 18:41:37.699: D/Vold(64): Volume emmc state changing 0 (No-Media) -> 2 (Pending)
01-07 18:41:37.699: D/Vold(64): Volume emmc state changing 2 (Pending) -> 1 (Idle-Unmounted)
01-07 18:42:09.832: D/VoldCmdListener(64): volume list
01-07 18:42:21.902: D/VoldCmdListener(64): volume mount /mnt/emmc
01-07 18:42:21.902: I/Vold(64): /dev/block/vold/179:9 being considered for volume emmc
01-07 18:42:21.902: D/Vold(64): Volume emmc state changing 1 (Idle-Unmounted) -> 3 (Checking)
01-07 18:42:23.339: I/Vold(64): Filesystem check completed OK
01-07 18:42:23.355: I/Vold(64): Device /dev/block/vold/179:9, target /mnt/emmc mounted @ /mnt/secure/staging
01-07 18:42:23.355: D/Vold(64): Volume emmc state changing 3 (Checking) -> 4 (Mounted)
01-07 18:42:23.394: D/VoldCmdListener(64): volume mount /mnt/sdcard
01-07 18:42:23.394: I/Vold(64): /dev/block/vold/179:2 being considered for volume sdcard
01-07 18:42:23.394: D/Vold(64): Volume sdcard state changing 1 (Idle-Unmounted) -> 3 (Checking)
01-07 18:42:25.910: I/Vold(64): Filesystem check completed OK
01-07 18:42:25.910: I/Vold(64): Device /dev/block/vold/179:2, target /mnt/sdcard mounted @ /mnt/secure/staging
01-07 18:42:25.910: D/Vold(64): Volume sdcard state changing 3 (Checking) -> 4 (Mounted)
01-07 18:42:26.382: D/VoldCmdListener(64): asec list

found something to look through at /sys/, many many things to look at though.