work in progress.
Looks like UARTA is using the ULPI pins as noted here (https://github.com/u-boot/u-boot/blob/master/arch/arm/mach-tegra/tegra30/pinmux.c#L238) So we know we can setup our UARTA and UARTD on the ULPI pins
#if defined UARTA
/* set pinmux for uart-a (nexus 7) */
reg_write(PINMUX_BASE, PINMUX_AUX_ULPI_DATA0_0, 0b00000110); /* tx */
reg_write(PINMUX_BASE, PINMUX_AUX_ULPI_DATA1_0, 0b00100110); /* rx */
#elif defined UARTD
/* set pinmux for uart-d (ouya */
reg_write(PINMUX_BASE, PINMUX_AUX_ULPI_CLK_0, 0b00000110); /* tx */
reg_write(PINMUX_BASE, PINMUX_AUX_ULPI_DIR_0, 0b00100110); /* rx */
#endif
To get your platform key use this command in the tegra30-debrick directory.sudo ./fusee-launcher/fusee-launcher.py –-tty ./fusee-launcher/dump-sbk-via-usb.bin
Add the -P parameter at the end to specify the product_id if "No TegraRCM device found" is the output. For the Surface RT 1 this is 7130.
This will output a lot of things. Look for the line with hello world, after that line something like this b'e57de3bab6cb499d874d5772cb219f0101042c20'
should show up. Remove the b, the two ' and the last 8 remaining characters. This is your platform key. It is used to encrypt and decrypt the BCT and the firststage bootloader