Booting from SD on T420

[sestulak]

Allright I´ve bought T420 for 20€ as I wrote here in the past, but it does not come with HDD and beacouse I am owner of one T420 allready I really don´t need new one. Yes I´m planning buying 120GB SSD in the future but now I´m thinking abou booting some light linux distro from an SD card. I know that there is no such option in the BIOS but I ´m thinking that experts such as you might help me around this. And I´m familliar fith alternative option such as SD card reader for ExpressCard and so but these solutiobs usualy cost as much as 120 GB SSD.
Thanks for any help

[axur-delmeria]

It's impossible to boot from the T420's SD card slot straight from the BIOS, period.

Laptops that can boot from SD/MMC/XD cards etc. are able to do so because the card reader hardware is USB-based, and leverages the USB boot routines built into the BIOS.

The T420's SD card reader is a PCIe device. In order to boot from it, a device-specific boot code must be written and included into the BIOS. Unfortunately, no such code exists.

The next best thing is to install GRUB (the usual Linux boot loader) on a USB flash drive, and configure it to include the drivers for the SD card slot so that the rest of the Linux OS can be installed there.
There's a guide for old Ubuntu versions here, the commands might be different in newer versions, but the concept it the same.