Board:lenovo/t520

Status

Issues:

• no MRC cache (longer boot time)
• yellow USB port isn't powered in power-off state.
• S3 (Suspend to RAM) - system switch off
• discrete GPU
• display port connected to discrete GPU
• native RAM init fails training

Tested:

• ultraabay sata
• RAM module combinations of 4G+0, 0+4G
• USB ports
• Video (both internal and VGA)
• Expresscard slot (including hotplugging)
• LAN
• mini-PCIe slot WLAN
• Linux (through SeaBIOS-as-payload)
• trackpoint

Not tested:

• firewire
• eSATA
• msata/ usb wwan slot
• SD card slot
• Sound (integrated speakers, integrated mic, external headphones, external mic)
• Thermal management
• Fingerprint reader
• Webcam
• touchpad
• Fn hotkeys
• Thinklight
• bluetooth
• dock
• msata

proprietary components status

• CPU Microcode
• VGA option rom (optional): you need it if you want graphics in SeaBIOS but most payloads should work without it (text mode or corebootfb mode)
• ME(Management Engine) => you do not have to touch it(just leave it where it is)
• GbE(Gigabit Ethernet embedded mac) => you do not have to touch it(just leave it where it is)

Code

• The code has been merged into coreboot master

 $ git clone http://review.coreboot.org/p/coreboot

Flashing

T520 has a ST 25PX64VG 8M flash chip in a VDFPN8 package.

Next to the flash chip is a connector solder place "J100" where it is connected to.

1 N/C
2 N/C
3 /CS
4 VCC
5 MISO
6 /HOLD
7 /WP
8 CLK
9 GND
10 MOSI

Flash layout: FLREG0: 0x00000000

 Flash Region 0 (Flash Descriptor): 00000000 - 00000fff 

FLREG1: 0x07ff0500

 Flash Region 1 (BIOS): 00500000 - 007fffff 

FLREG2: 0x04ff0003

 Flash Region 2 (Intel ME): 00003000 - 004fffff 

FLREG3: 0x00020001

 Flash Region 3 (GbE): 00001000 - 00002fff 

FLREG4: 0x00000fff

 Flash Region 4 (Platform Data): 00fff000 - 00000fff (unused)

Vendor firmware locks the flash and so you need to flash externally (unless until someone figures out a way around it).