XO4 Bringup

This page lists goals and plans for initial bringup of the XO 4 A1 motherboard, the first prototype of the XO-4 Laptop.

Status

Note that a check in any one of the two columns is generally sufficient to prove that the hardware works.

Bringup status

Subsystem	OFW	Linux	Kernel maintainer	Notes/Reference
CPU Boot	X	X
Serial port	X	X		#12045 still open
Host/EC communications	X		dilinger / pgf	XO_1.75_HOST_to_EC_Protocol
Host/EC programming	X	NA
Keyboard	X		pgf
Touchpad	X		pgf
USB	X		cjb
SD (Int/Ext)	X	X	cjb	Ext SD cards are being detected read-only by Linux in some machines
eMMC	X	X	cjb
DCON	X		cjb
Framebuffer display	X		jnettlet
Xorg	NA		jnettlet
Audio playback (Int/Ext)	X		saadia
Audio recording (Int/Ext)			saadia
SDIO WLAN	X	X	cjb
Battery charging	X	NA
Touchscreen			pgf
OFW SPI Flash Prog.	X	NA
Camera	X		jnettlet
SMP	NA		dilinger
Battery driver	X		pgf
OLS			saadia
Switches (ebook, lid)			pgf
Internal RTC			saadia
External RTC			saadia
Accelerometer			saadia
Suspend/resume			dilinger
CPU frequency changing

Goals

The goal of a A-phase board bring-up is get a small number of boards to an acceptable state of functionality. At this point, a larger number of boards are modified to match and distributed for both extended testing of basic functionality (esp. memory stability) and development of software to access further functionality.

The following are the goals of this bringup:

• EC code booting and controlling the power sequencing properly
• CPU booting OFW
• Reliable memory and internal SD operation from OFW
• Reliable use of USB ports from OFW
• Support for the display and keyboard from OFW and Linux
• Support for reprogramming the EC SPI Flash from CPU

Non-goals

We can go home even if these aren't working

• Proper operation of audio interface
• Proper operation of the wireless LAN
• Camera
• Linux

Personnel

• Wad (EE), Gary Chiang (EE), Richard (EC/OFW), Mitch (OFW), Paul (EC/Linux), from OLPC
• Mars (PM), Eddie (PM), Beckham Chen (EE), from Quanta R&D