When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.com>
Raspberry firmware used to pass a FDT blob at a fixed address (0x100),
but this is not true anymore. The address now depends on both the
memory size and the blob size [1].
If one wants to passthrough this FDT blob to the kernel, the most
reliable way is to save its address from the r2/x0 register in the
U-Boot entry point and expose it in a environment variable for
further processing.
This patch just does this:
- save the provided address in the global variable fw_dtb_pointer
- expose it in ${fdt_addr} if it points to a a valid FDT blob
There are many different ways to use it. One can, for example, use
the following script which will extract from the tree the command
line built by the firmware, then hand over the blob to a previously
loaded kernel:
fdt addr ${fdt_addr}
fdt get value bootargs /chosen bootargs
bootz ${kernel_addr_r} - ${fdt_addr}
Alternatively, users relying on sysboot/pxe can simply omit any FDT
statement in their extlinux.conf file, U-Boot will automagically pick
${fdt_addr} and pass it to the kernel.
[1] https://www.raspberrypi.org/forums//viewtopic.php?f=107&t=134018
Signed-off-by: Cédric Schieli <cschieli@gmail.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tom Rini
Cédric Schieli