[yocto] [meta-raspberrypi][PATCH v3] u-boot: Simplify boot script

Tom Rini trini at konsulko.com
Sat Nov 5 10:47:12 PDT 2016

On Sat, Nov 05, 2016 at 12:50:07PM +1100, Jonathan Liu wrote:

> +++ b/recipes-bsp/u-boot/files/rpi-fdt-addr.patch
> @@ -0,0 +1,77 @@
> +From 0bb380da174f9372a706b5a4914a4c06ad7fbfdf Mon Sep 17 00:00:00 2001
> +From: Jonathan Liu <net147 at gmail.com>
> +Date: Sat, 5 Nov 2016 12:43:47 +1100
> +Subject: [PATCH] rpi: Set fdt_addr_r to device tree address from firmware
> +
> +The Raspberry Pi firmware will load a patched device tree blob into
> +memory if a trailer is added to the U-Boot binary indicating it is
> +DT-capable using "mkknlimg --dtok" or if using firmware release 4.4
> +or later and no trailer is present.
> +
> +In this case, U-Boot is executed as if it were the Linux kernel and
> +the r2 register is set to the address of the patched device tree blob
> +in memory. We can check if the blob is loaded by checking for the
> +device tree magic constant 0xedfe0dd0 (little endian equivalent of
> +the big endian 0xd00dfeed constant) at the address stored in r2.
> +If the magic constant is present, the fdt_addr_r variable is set to
> +r2 so that U-Boot scripts can access the patched device tree blob.
> +
> +Upstream-Status: Pending

Please note that upstream we are looking at:


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