OLPC/Kernel

Kernel

• power management
• CPU frequency scaling (current GX2 does not support it)
• suspend to RAM (when?)
• at the drop of the hat
• in ebook mode and allow the DCON ASIC to handle video refresh
• shutdown particular unused devices
• memory management
• compressed caching
• relocation of code/data, increasing page locality, thus decreasing memory footprint
• out of memory conditions
• current code just says score = heuristic(process) according to alan
• probably easy to set, just requires a deviation from the normal kernel
• Filesystem
• Stable JFFS2 with xattr support
• device drivers
• Audio: AC97 codec (probably adding support for the AD1888)
• Power management for this chip is critical - good amount of work to do here
• Input devices: keyboard, trackpad (supporting pointing, scrolling, and possibly graphical input).
• additional buttons adjacent to screen for use in E-Book/tablet mode
• wireless: Marvell (usb version of the 8388 (google for 88w8388))
• Status indicators, visible with lid closed:
• Power
• Battery status
• Wifi active
• need an fbdev driver because there will be no vesa mode on the video card
• AMD Geode GX2 (CS5535)
• Requires power management updates
• AMD Claims that unused parts of the chipset will "turn themselves off automatically if they aren't used" but that needs investigation
• ALSA driver on the website supports PM but we have to do investigations of the IP around it - did it come from the windows driver or not?

• Video card (GX2 embedded): dealt with by X.org only?
• DCON ASIC (bridge from CPU to display) is in the process of design.
• note that this chip might also generate keyboard events off the display part of the laptop
• also handles unswizzling for the display into a standard frame buffer
• poor man's antialiasing
• control of refresh speed
• local frame buffer to allow the CPU to be put into S3 while the panel lives on
• rotation (maybe)