[System description] We have designed a MPC855T system hooked up to an Altera '400 EPLD. The FPGA perform the realtime JPEG compression of the image data stream, piping it directly to ATA disk by means of DMA.
The Altera EPLD is interfaced to the PowerPC through the PCMCIA port A, and is designed to present itself as a multifunctional PCMCIA device of which the first is the ATA disk (controller) connected to another port of the EPLD. The ATA disk is in other words connected to a switched bus (MUX) internal to the EPLD and at one time either connected to the PCMCIA (PowerPC) interface or to the JPEG compression block but never both. [Actual question] It would be beneficial to have a filesystem that allows for linear write of large files (~20-50GB) and a partitioning scheme that allows the ATA disk to be removed and later plugged into an IBM PC. The partitioning and formatting must be possible to perform over the MPC855T PCMCIA interface by PowerPC/Linux. The free space must be absolutely free (no interspaced file system nodes) since the EPLD will perform raw write form start LBA outwards. Upon completion the data will be backannotated into the file system by means of patching file tables with start LBA and end LBA. No CRC/ECC. FAT16 is well documented and would have been a perfect solution. But 2GB partition size is unfortunately unacceptable. FAT32 seems more obscure and is not so well documented. Any good references? Minix is told to be simple but where is it documented? Any other filesystems w/docs? (MAC/SUN/ISO filesystems&partitioning?) Also, does PPC/Linux now detect PCMCIA ATA drives out of the box without any resort to interrupt rerouting and the like? (The system will - when the HW will arrive in three weeks time - boot from Flash with initrd, not from the PCMCIA ATA disk.) -- Geir Frode Raanes Norsk Elektro Optikk A/S [www.neo.no] ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
