I am booted off sata by doing the following:
I took David's image:
http://www.mininodes.com/uploads/cubieboard2-centos-image.img.tar.gz
And first dd it to a 4Gb mSD card. I used gparted to delete all three partitions. This way I was assured to get the uboot David used.
Then I dd it to a 80Gb sata drive. I use gparted to increase the size of the / partition.
I put the uboot only mSD card in the slot and attached to sata drive and it booted right up. Here is what the serial console showed.
U-Boot SPL 2015.07-rc1-00513-g5bcec54 (Jun 17 2015 - 13:48:34) DRAM: 1024 MiB CPU: 912000000Hz, AXI/AHB/APB: 3/2/2
U-Boot 2015.07-rc1-00513-g5bcec54 (Jun 17 2015 - 13:48:34 +0530) Allwinner Techn ology
CPU: Allwinner A20 (SUN7I) I2C: ready DRAM: 1 GiB MMC: SUNXI SD/MMC: 0 *** Warning - bad CRC, using default environment
HDMI connected: Setting up a 1920x1080 hdmi console In: serial Out: vga Err: vga SCSI: SUNXI SCSI INIT Target spinup took 0 ms. AHCI 0001.0100 32 slots 1 ports 3 Gbps 0x1 impl SATA mode flags: ncq stag pm led clo only pmp pio slum part ccc apst Net: eth0: ethernet@01c50000 starting USB... USB0: USB EHCI 1.00 USB1: USB OHCI 1.0 USB2: USB EHCI 1.00 USB3: USB OHCI 1.0 scanning bus 0 for devices... 1 USB Device(s) found scanning bus 2 for devices... 1 USB Device(s) found scanning bus 1 for devices... 2 USB Device(s) found scanning bus 3 for devices... 1 USB Device(s) found Hit any key to stop autoboot: 0 switch to partitions #0, OK mmc0 is current device ** Invalid partition 1 ** scanning bus for devices... Device 0: (0:0) Vendor: ATA Prod.: WDC WD800BEVS-75 Rev: 04.0 Type: Hard Disk Capacity: 76319.0 MB = 74.5 GB (156301488 x 512) Found 1 device(s).
SCSI device 0: Device 0: (0:0) Vendor: ATA Prod.: WDC WD800BEVS-75 Rev: 04.0 Type: Hard Disk Capacity: 76319.0 MB = 74.5 GB (156301488 x 512) ... is now current device Scanning scsi 0:1... Found /extlinux/extlinux.conf Retrieving file: /extlinux/extlinux.conf 327 bytes read in 57 ms (4.9 KiB/s) Ignoring unknown command: ui Ignoring malformed menu command: autoboot Ignoring unknown command: totaltimeout centos Options 1: centos Enter choice: 1: centos Retrieving file: /initramfs-4.0.0-1.el7.armv7hl.img 66687488 bytes read in 1838 ms (34.6 MiB/s) Retrieving file: /vmlinuz-4.0.0-1.el7.armv7hl
and so forth.
So looks good.