Bug#498568: Debian cannot be installed on bootable SD cards
Package: debian-installer
Version: 20080522
http://wiki.gpl-devices.org/wiki/Installing_Linux_on_booting_SD_card
Recently, BIOS vendors have been starting to implement a 'boot from SD card'
feature, much like they have added 'boot from USB memory stick' some years ago.
The only SD-card host controller that I've seen this implemented for is SDHCI
compliant host controllers.
While this is a nice feature to support, for most systems it is just a gimmick
and not something neccessarry.
However, there are hand-held devices such as netbooks in the pipeline which do
not have any other mass storage device. No hard disk and no IDE-attached flash
disk or the like. They just have one (more likely two or more) SD card slots
and you install and store not only your data but the entire operating system on
that SD card.
Furthermore, there are products like Samsung moviNAND which are basically a
SDcard in a BGA package that can be soldered onto a PCB. So from a protocol and
software point of view it is a SD card, but it is mechanically soldered onto
the board. Such device have gained some popularity in ARM-based designs, but
we'll likely see them in the x86 world, too.
Installer requirements
The distribution installation initrd needs to
1. include and auto-load the sdhc.ko and sdhci_pci.ko kernel modules
2. create the /dev/mmcblk* device nodes as per udev/hotplug events
The actual distribution installation program needs to
1. recognize /dev/mmcblk* as block devices that can be used as target device
2. use a grub-install or similar program that can discover the bios drive number to /dev/mmcblk* device name mapping
debian-installer doesn't currently (debian testing installation image of
2008-09-08) support this, and thus Debian cannot be installed on a system with
bootable SD card.
--
- Harald Welte <HaraldWelte@viatech.com> http://linux.via.com.tw/
============================================================================
VIA Open Source Liaison
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