README.hardware: Add Atom PC image flashing documentation

Cover the basics of flashing images to physical media for the Atom PC MACHINE,
as well as dealing with BIOSs that can only boot USB media in USB-ZIP mode.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>

1 files changed, 75 insertions, 0 deletions

diff --git a/README.hardware b/README.hardware
index 270c71a1f..fe384b37d 100644
--- a/README.hardware
+++ b/README.hardware
@@ -433,4 +433,79 @@ following differences:
     $ cp ./tmp/deploy/images/gnu-tar /path/to/my-cf-card/gnu-tar
 
 
+Intel Atom based PCs and devices (atom-pc)
+==========================================
 
+The atom-pc MACHINE is tested on the following platforms:
+
+  o Asus eee901
+  o Acer Aspire One
+  o Toshiba NB305
+  o Intel Embedded Development Board 1-N450 (Black Sand)
+
+and is likely to work on many unlisted atom based devices. The MACHINE type
+supports ethernet, wifi, sound, and i915 graphics by default in addition to
+common PC input devices, busses, and so on.
+
+Depending on the device, it can boot from a traditional hard-disk, a USB device,
+or over the network. Writing poky generated images to physical media is
+straightforward with a caveat for USB devices. The following examples assume the
+target boot device is /dev/sdb, be sure to verify this and use the correct
+device as the following commands are run as root and are not reversable.
+
+Hard Disk:
+  1. Build a directdisk image format. This will generate proper partition tables
+     that will in turn be written to the physical media. For example:
+
+     $ bitbake poky-image-minimal-directdisk
+  
+  2. Use the "dd" utility to write the image to the raw block device. For example:
+
+     # dd if=poky-image-minimal-directdisk-atom-pc.hdddirect of=/dev/sdb
+
+USB Device:
+  1. Build an hddimg image format. This is a simple filesystem without partition
+     tables and is suitable for USB keys. For example:
+
+     $ bitbake poky-image-minimal-live
+
+  2. Use the "dd" utility to write the image to the raw block device. For
+     example:
+
+     # dd if=poky-image-minimal-live-atom-pc.hddimg of=/dev/sdb
+
+  If the device fails to boot with "Boot error" displayed, it is likely the BIOS
+  cannot understand the physical layout of the disk (or rather it expects a
+  particular layout and cannot handle anything else). There are two possible
+  solutions to this problem:
+
+  1. Change the BIOS USB Device setting to HDD mode. The label will vary by
+     device, but the idea is to force BIOS to read the Cylinder/Head/Sector
+     geometry from the device.
+
+  2. Without such an option, the BIOS generally boots the device in USB-ZIP
+     mode.
+
+     a. Configure the USB device for USB-ZIP mode:
+     
+     # mkdiskimage -4 /dev/sdb 0 63 62
+
+     Where 63 and 62 are the head and sector count as reported by fdisk.
+     Remove and reinsert the device to allow the kernel to detect the new
+     partition layout.
+
+     b. Copy the contents of the poky image to the USB-ZIP mode device:
+
+     # mount -o loop poky-image-minimal-live-atom-pc.hddimg  /tmp/image
+     # mount /dev/sdb4 /tmp/usbkey
+     # cp -rf /tmp/image/* /tmp/usbkey
+
+     c. Install the syslinux boot loader:
+
+     # syslinux /dev/sdb4
+
+  Install the boot device in the target board and configure the BIOS to boot
+  from it.
+
+  For more details on the USB-ZIP scenario, see the syslinux documentation:
+  http://git.kernel.org/?p=boot/syslinux/syslinux.git;a=blob_plain;f=doc/usbkey.txt;hb=HEAD