I installed TC2.10 on a SD-card plugged into an USB2.0 INternal _MULTI_ card reader.
After successful booting I wondered why fdisk -l did NOT show a device corresponding to the SD-card
During thinking (and surfing) on this topic quite a bit of time I realized the following:
1. The BIOS detects the USB2.0 INternal _MULTI_ card reader and each of its 4 slots.
2. The BIOS lists only those slots with plugged-in SD-cards in a special boot menu, when I hold down F8 key during boot.
3. Choosing to boot the SD-card with installed TC then grub boot loader is started.
4. Grub loads bzImage and tinycore.gz into memory (RAM) and TC takes over to rule the PC.
5. Now TCLinux is on its own to care about devices ... but it seems to be not so equipped as the BIOS ...
Finally I found a very illuminating discourse on
Using a USB Card Reader in Linux It explains that the kernel option “Probe all LUNs on each SCSI device” (CONFIG_SCSI_MULTI_LUN) must be enabled so that a linux OS is able to detect ALL card slots of a MULTI card reader during the OS' boot process.
I haven't yet tried the alternative method (also mentioned therein) of adding the line
options scsi_mod max_scsi_luns=8
to /etc/modules.conf (which then had to be made persistent in order to substitute its original copy on each boot ...)
But I can confirm that the also mentioned third method of kinda "deferred" setting of a certain kernel parameter is successful:
echo 8 > /sys/module/scsi_mod/parameters/max_luns
Having issued this command I just plugged in an USB2.0 EXternal MULTI card reader equipped with a SD-card and now fdisk -l DID show up the SD-card as /dev/sdd1
Note: Booting with this second reader+card being ALREADY plugged-in will provide the device ONLY IF you plug out the reader's USB cable, then issue the above command and then plug it in again !
(I don't know if there might be a method of soft re-initialization of the USB system ...)
So after all SETting the respective kernel parameter CONFIG_SCSI_MULTI_LUN in the future kernel config seems to be the most effective way.
Thanks in advance for considering ...
P.S.
cat /sys/module/scsi_mod/parameters/max_luns
reveals the default value 1 .
So IMHO TC would be able to automatically provide a device during its boot if the logically FIRST slot of the INternal MULTI card reader was the one equipped with the SD-card ... with 4 slots the probability of success is obviously 25 %