[U-Boot] [PATCH v2] common: fit: Allow U-Boot images to be booted

[Robert P. J. Day]

On Wed, 20 Jul 2016, Mario Six wrote:

> In certain circumstances it comes in handy to be able to boot into a second
> U-Boot. But as of now it is not possible to boot a U-Boot binary that is inside
> a FIT image, which is problematic for projects that e.g. need to guarantee a
> unbroken chain of trust from SOC all the way into the OS, since the FIT signing
> mechanism cannot be used.
>
> This patch adds the capability to load such FIT images.
>
> An example .its snippet (utilizing signature verification) might look
> like the following:
>
> images {
> 	firmware at 1 {
> 		description = "2nd stage U-Boot image";
> 		data = /incbin/("u-boot-dtb.img.gz");
> 		type = "firmware";
> 		arch = "arm";
> 		os = "u-boot";
> 		compression = "gzip";
> 		load = <0x8FFFC0>;
> 		entry = <0x900000>;
> 		signature at 1 {
> 			algo = "sha256,rsa4096";
> 			key-name-hint = "key";
> 		};
> 	};
> };

  i'm sure i'm about to embarrass myself, but the above represents
loading a second version of u-boot into RAM, no? but i thought u-boot
didn't support being run out of RAM (except in special circumstances).
so what am i misunderstanding here?

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
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