SD card support comes to RISC OS
Posted by Steve Revill Thu, 07 Jun 2012 21:26:00 GMT
RISC OS Open and Piccolo Systems are very pleased to announce the release of a general-purpose MMC/SD filing system for RISC OS.
ROOL have signed an agreement with Piccolo Systems to publish the source code to the driver and related software under an Open Source licence within the ROOL CVS repository. It will be integrated into the OMAP3 developer ROM build, found on our downloads pages to give native support for SD cards on the Beagleboard, Beagleboard-xM, DevKit8000 (untested) and IGEPv2 (untested).
The new code, published today, includes:
- SDIODriver – the driver for SDHCI controllers
- SDFS – a FileCore filing system that uses SDIODriver to access data stored on a wide range of memory cards
- SDCMOS – works with recent bootloader scripts to ensure CMOS settings persist across reboots, even for users without EEPROM carrier boards, and without requiring the boot SD card to be left in the slot at all times
- OMAP3 HAL – adds hardware-specific declarations and support routines to enable SDIODriver to drive the main SD slot on popular boards
Supported memory card types include MMC, MMCplus, RS-MMC, MMCmobile, SD, SDHC, SDXC, MiniSD, MicroSD and MicroSDHC, of capacities up to 256 GB. Access speeds of up to 14.5 MB/s (card dependent) have been measured on Beagleboards.
Over the past couple of months, this work has already benefited RISC OS, with changes, bug fixes and other improvements already in CVS for the following components:
- FileCore – many changes and improvements, including faster mounting of media
- DOSFS – tweaks and fixes, including allowing construction of bootable DOS-formatted media
- HForm – support for formatting SD cards, amongst many other bug fixes
- SyncLib – new library of architecture-independent synchronisation primitives
- SDFSFiler – a desktop front-end to the SD filing system
At the moment, the SDFS code should be considered a beta release until we are ready to call it stable (it will be one of the deciding factors going into a 5.20 stable release of RISC OS).