> Out of curiousity, how are the SD cards on bootup, compared to the ease
> of using CF cards, and the pain (well the pains I had) of using the USB
> drivers?
The onboard EEPROM contains code to talk to SD and the board actually
boots directly to SD. The handoff from the bootrom to the SD card is
very similar to x86 bootup-- the first 512 bytes of the SD card (the
MBR) is loaded into ram and jumped into. The code inside the MBR
calls the BOOTROM routines to read more blocks from the SD card
(similar to x86 DOS int 13h) and bootstrap itself.
Currently, our MBR code (Only 446 bytes available after partition
table) loads in a kernel and an initrd from dedicated partitions on
the SD card and starts Linux. The initrd contains the FPGA bitstream
and the Linux driver modules for SD. These are loaded (along with
modules for the ethernet and serial ports) and then the initrd does a
pivot_root to the SD EXT2 filesystem and then frees the initrd. There
is no onboard flash on the TS-7300-- only SD.
//Jesse Off
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