PC Engines APUx flashing with iPXE usage

Intro

Name of used APUx serial console visible in PC: ttyUSB0
IP of used PXE server: 192.168.0.108

Requirements

Ethernet connection to the network
iPXE server has to be online and in the same network
PXE boot has to be enabled in SeaBIOS options
OS with installed flashrom
Serial connection between APUx and PC

Flashing procedure

Open APUx serial console. You can use minicom to do that. Parameters of connection:
- Baudrate: 115200
- Data bits: 8
- Parity: None
- Stop bits: 1
```
sudo minicom -b 115200 -o -D /dev/<name of APUx serial console visible in PC>
```
E.g.

sudo minicom -b 115200 -o -D /dev/ttyUSB0
Turn on APUx.

When following communicate appears:

Press F10 key now for boot menu, N for PXE boot

press N to enter to the PXE boot menu.

---------------- iPXE boot menu ----------------
ipxe shell
autoboot

Select ipxe shell. You have to hurry because default option is autoboot and it will be selected after few seconds.
After successful running the ipxe shell the following prompt will appear
```
iPXE>
```
Now you have to type commands showed below:
```
dhcp net1
set filename pxelinux.0
set next-server 192.168.0.108
chain tftp://${next-server}/${filename}
```
The X number in netX interface can be different depending on the connector to which Ethernet is connected. If selected interface is connected to network information similar to the showed below should appear:
```
Configuring (net1 00:0d:b9:47:bb:e1).................. ok
```
MAC address should be displayed. If there is no MAC address that means that there is no connection to the network for that interface.

IP placed next to next-server should be correct IP of used PXE server. In case http server is used use http:// instead of tftp://

After few seconds PXE server boot menu should appear:

                lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqk
                x         PXE server boot menu          x
                tqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqu
                x Install                               x
                x Debian-netboot                        x
                x Voyage-netinst                        x
                x                                       x
                x                                       x
                x                                       x
                x                                       x
                x                                       x
                x                                       x
                x                                       x
                x                                       x
                x                                       x
                mqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj

                        Press [Tab] to edit options

Select Debian-netboot because it's the only OS with installed flashrom available in PXE server boot menu when instruction is being written. After that OS booting should start.

Number of OSes can be increased in the future.

When Legacy Console Redirection is turned on displayed characters are doubled. It's beacause iPXE is outputting data to the serial console and to the screen, which is emulated on serial console.

When a prompt similar to the shown below appears:
```
pcengines login:
```
Type root as login. Then next prompt should appear:
```
Password:
```
Type root as password to finish logging process.

Steps shown above can be automated using Robot Framework.

Now you can start flashing process. To flash firmware with flashrom usage type:

APU1

flashrom -w <directory to ROM> -p internal -c "MX25L1605A/MX25L1606E/MX25L1608E"

APU2/3/4/5

flashrom -w <directory to ROM> -p internal

E.g. (APU2):

flashrom -w /tmp/coreboot.rom -p internal

After correct firmware flashing the following message should appear:

Reading old flash chip contents... done.
Erasing and writing flash chip... Erase/write done.
Verifying flash... VERIFIED.

Now you can reboot the platform.

Sometimes after APUx flashing platform doesn't turn on after warm boot. In that situation cold boot is required.

Sending ROM image to APUx device with scp usage

To send ROM image to device you can use scp.
```
cd <directory with ROM image>
scp <ROM image> root@<IP of APUx to flash>:<directory to store ROM image on APUx>
```
E.g (APU2).:
```
cd /home/me/coreboot/build
scp coreboot.rom root@192.168.0.123:/tmp
```
Then to flash APU2 type in the serial console:
```
cd
flashrom -w /tmp/coreboot.rom -p internal
```

Enabling PXE boot in SeaBIOS

Turn on APUx.
When the following prompt shows:
```
Press F10 key now for boot menu
```
Press F10.
Then menu similar to the showed below should appear:
```
Select boot device:

1. Payload [setup]
2. Payload [memtest]
```
Select 1. Payload [setup] by pressing 1.

Next menu will be showed:

### PC Engines apu2 setup v4.5.7 ###
Boot order - type letter to move device to top.

a USB 1 / USB 2 SS and HS
b SDCARD
c mSATA
d SATA
e mPCIe1 SATA1 and SATA2
f iPXE (disabled)


r Restore boot order defaults
n Network/PXE boot - Currently Disabled
u USB boot - Currently Enabled
l Legacy console redirection - Currently Disabled
w Enable BIOS write protect - Currently Disabled
x Exit setup without save
s Save configuration and exit

Select n Network/PXE boot - Currently Disabled by pressing n. This position should change to n Network/PXE boot - Currently Enabled.

Now you can reboot platform by choosing s Save configuration and exit, so press s to do that.