FreeBSD 7.x (which is the base OS for FreeNAS 0.70) does boot just fine.

PATA port issue

FreeBSD is unable to see the PATA port on ICH7, unless the chip is set to 'compatibility' mode and SATA is disabled entirely in the BIOS. This does not seem to affect FreeBSD's ability to enumerate and use the SATA ports, though, even in AHCI mode.

amd64 version of FreeNAS 0.70 cannot see the PATA port whatsoever. The solution is to use the i386 version, or add the following to /boot/device.hints:

hint.ata.0.at="isa"

hint.ata.0.port="0x1F0"

hint.ata.0.irq="14"

Shutdown issue

FreeBSD 7.x is unable to completely shut down the device. It is a known bug currently in the works:

It turns out that if you turn off USB in the BIOS, the problem disappears. So for now it's your choice whether to live without USB connectivity or without programmatic power-off

eSATA support

Installation process

Switch BIOS to boot from CD and reboot the NAS;
Add boot hints as follows (option 5 on LiveCD install, at 'OK' prompt add following, then type 'boot' to continue):

set hint.ata.0.at="isa"
set hint.ata.0.port="0x1F0"
set hint.ata.0.irq="14"
set console="comconsole,vidconsole"

Once FreeNAS finishes loading, open your browser and navigate to the NAS IP address (192.168.1.250)
Login as admin/freenas
Change and save /etc/ttys as follows from Advanced Options, File Editor:

ttyd0   "/usr/libexec/getty std.9600"   vt100   on secure

Go to System -> Advanced -> Command and type in "kill -HUP 1" and click on Execute to get the login prompt from your Putty (etc.) serial connection.
Login as root/freenas
Type: /bin/sh (enter) and /etc/rc.initial to get the Menu to set IP and install the OS on the IDE drive.
At the prompt, select 9 -> Install on HD/USB. Then select 3 -> Install Full OS and follow the prompt to select the 128 MB IDE drive as the system drive.
Once done, reboot (remove USB CD ROM)
Bounce NAS, enter BIOS and select DOM as boot device
FreeNAS should boot from DOM, interrupt the boot loader again and add hints:

set hint.ata.0.at="isa"
set hint.ata.0.port="0x1F0"
set hint.ata.0.irq="14"
set console="comconsole,vidconsole"

Once online, go to the web console, login, and modify files as follows:

/boot/loader.conf

boot_multicons="YES"

boot_serial="YES"

comconsole_speed="9600"

console="comconsole,vidconsole"

/boot/device.hints

hint.ata.0.at="isa"

hint.ata.0.port="0x1F0"