[U-Boot] [PATCH v3 3/5] docs: Document verified-boot for sunxi a64
Jagan Teki
jagannadh.teki at gmail.com
Wed Dec 13 16:35:30 UTC 2017
On Wed, Dec 13, 2017 at 9:55 PM, Andre Przywara <andre.przywara at arm.com> wrote:
> Hi,
>
> On 13/12/17 16:16, Jagan Teki wrote:
>> On Wed, Dec 13, 2017 at 9:29 PM, Quentin Schulz
>> <quentin.schulz at free-electrons.com> wrote:
>>> Hi Jagan,
>>>
>>> On 13/12/2017 07:03, Jagan Teki wrote:
>>>> Add verified-boot documentation for sunxi a64 platform.
>>>>
>>>> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
>>>> ---
>>>> Changes for v3:
>>>> - Create separate document file
>>>> Changes for v2:
>>>> - New patch
>>>>
>>>> doc/README.sunxi | 193 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>> 1 file changed, 193 insertions(+)
>>>> create mode 100644 doc/README.sunxi
>>>>
>>>> diff --git a/doc/README.sunxi b/doc/README.sunxi
>>>> new file mode 100644
>>>> index 0000000..ef4f735
>>>> --- /dev/null
>>>> +++ b/doc/README.sunxi
>>>> @@ -0,0 +1,193 @@
>>>> +#
>>>> +# Copyright (C) 2017 Amarula Solutions
>>>> +#
>>>> +# SPDX-License-Identifier: GPL-2.0+
>>>> +#
>>>> +
>>>> +U-Boot on SunXi
>>>> +==============
>>>> +
>>>> +Tutorial describe all details relevant for U-Boot on Allwinner SunXi platform.
>>>> +
>>>> + 1. Verified Boot
>>>> +
>>>> +1. Verified Boot
>>>> +================
>>>> +
>>>> +U-Boot supports an image verification method called "Verified Boot".
>>>> +This is a brief tutorial to utilize this feature for the Sunxi A64 platform.
>>>> +You will find details documents in the doc/uImage.FIT directory.
>>>> +
>>>> +Here, we take Orangepi Win board for example, but it should work for any
>>>> +other boards including 32 bit SoCs.
>>>> +
>>>> +1. Generate RSA key to sign
>>>> +
>>>> + $ mkdir keys
>>>> + $ openssl genpkey -algorithm RSA -out keys/dev.key \
>>>> + -pkeyopt rsa_keygen_bits:2048 -pkeyopt rsa_keygen_pubexp:65537
>>>> + $ openssl req -batch -new -x509 -key keys/dev.key -out keys/dev.crt
>>>> +
>>>> +Two files "dev.key" and "dev.crt" will be created. The base name is arbitrary,
>>>> +but need to match to the "key-name-hint" property described below.
>>>> +
>>>> +2. FIT Input
>>>> +
>>>> +---------------------------------------->8----------------------------------------
>>>> +/dts-v1/;
>>>> +/ {
>>>> + description = "FIT image with single Linux kernel, FDT blob";
>>>> + #address-cells = <1>;
>>>> +
>>>> + images {
>>>> + kernel at 0 {
>>>> + description = "ARM64 Linux kernel";
>>>> + data = /incbin/("/path/to/linux/dir/arch/arm64/boot/Image.gz");
>>>> + type = "kernel";
>>>> + arch = "arm64";
>>>> + os = "linux";
>>>> + compression = "gzip";
>>>> + load = <0x50080000>;
>>>> + entry = <0x50080000>;
>>>> + hash at 1 {
>>>> + algo = "sha256";
>>>> + };
>>>> + };
>>>> +
>>>> + fdt at 0 {
>>>> + description = "Orangepi Win/Win+ Devicetree blob";
>>>> + data = /incbin/("/path/to/linux/dir/arch/arm64/boot/dts/allwinner/sun50i-a64-orangepi-win.dtb");
>>>> + type = "flat_dt";
>>>> + arch = "arm64";
>>>> + compression = "none";
>>>> + hash at 1 {
>>>> + algo = "sha256";
>>>> + };
>>>> + };
>>>> + };
>>>> +
>>>> + configurations {
>>>> + default = "conf at 0";
>>>> +
>>>> + conf at 0 {
>>>> + description = "Boot Linux kernel, FDT blob";
>>>> + kernel = "kernel at 0";
>>>> + fdt = "fdt at 0";
>>>> + signature at 0 {
>>>> + algo = "sha256,rsa2048";
>>>> + key-name-hint = "dev";
>>>> + sign-images = "kernel", "fdt";
>>>> + };
>>>> + };
>>>> + };
>>>> +};
>>>> +---------------------------------------->8----------------------------------------
>>>> +
>>>> +You need to change the two '/incbin/' lines, depending on the location of
>>>> +your kernel image and devicetree blob. The "load" and "entry" properties also
>>>> +need to be adjusted if you want to change the physical placement of the kernel.
>>>> +
>>>> +The "key-name-hint" must specify the key name you have created in the step 1.
>>>> +
>>>> +The FIT file name is arbitrary. Let's say you saved it into "fit.its".
>>>> +
>>>> +3. Compile U-Boot with FIT and signature enabled
>>>> +
>>>> +To use the Verified Boot, you need to enable the following two options:
>>>> + CONFIG_FIT
>>>> + CONFIG_FIT_SIGNATURE
>>>> +
>>>> + $ make orangepi_win_defconfig
>>>> + $ make CROSS_COMPILE=aarch64-linux-gnu-
>>>> +
>>>> +4. FIT Output
>>>> +
>>>> +After building U-Boot, you will see tools/mkimage. With this tool, you can
>>>> +create an image tree blob as follows:
>>>> +
>>>> + $ tools/mkimage -f fit.its -k keys -K dts/dt.dtb -r -F fitImage
>>>> +
>>>> +The -k option must specify the key directory you have created in step 1.
>>>> +
>>>> +A file "fitImage" will be created. This includes kernel, DTB,
>>>> +hash data for each of the three, and signature data.
>>>> +
>>>> +The public key needed for the run-time verification is stored in "dts/dt.dtb".
>>>> +
>>>> +5. Compile Verified U-Boot
>>>> +
>>>> +Since the "dt.dtb" has been updated in step 4, you need to re-compile the
>>>> +U-Boot.
>>>> +
>>>> + $ make CROSS_COMPILE=aarch64-linux-gnu-
>>>> +
>>>> +The re-compiled "u-boot.bin" is appended with DTB that contains the public key.
>>>> +
>>>> +6. Flash the image
>>>> +
>>>> +Flash the "fitImage" to a storage device (SD, NAND, eMMC, or whatever) on your
>>>> +board.
>>>> +
>>>> +7. Boot verified kernel
>>>> +
>>>> +Load the fitImage to memory and run the following from the U-Boot command line.
>>>> +
>>>> + > bootm <addr>
>>>> +
>>>> +Here, <addr> is the base address of the fitImage.
>>>> +
>>>> +If it is successful, you will see messages like follows:
>>>> +
>>>> +---------------------------------------->8----------------------------------------
>>>> +=> setenv bootargs console=ttyS0,115200 earlyprintk root=/dev/mmcblk0p1 rootwait
>>>> +=> ext4load mmc 0:1 $kernel_addr_r /boot/fitImage
>>>> +16321738 bytes read in 1049 ms (14.8 MiB/s)
>>>> +=> bootm $kernel_addr_r
>>>> +## Loading kernel from FIT Image at 40080000 ...
>>>> + Using 'conf at 0' configuration
>>>> + Verifying Hash Integrity ... OK
>>>> + Trying 'kernel at 0' kernel subimage
>>>> + Description: ARM64 Linux kernel
>>>> + Type: Kernel Image
>>>> + Compression: gzip compressed
>>>> + Data Start: 0x400800e4
>>>> + Data Size: 6884659 Bytes = 6.6 MiB
>>>> + Architecture: AArch64
>>>> + OS: Linux
>>>> + Load Address: 0x50080000
>>>> + Entry Point: 0x50080000
>>>> + Hash algo: sha256
>>>> + Hash value: 6808fe51ea3c15f31c4510d2701d4707b56d20213c9da05bce79fb53bf108f1a
>>>> + Verifying Hash Integrity ... sha256+ OK
>>>> +## Loading fdt from FIT Image at 40080000 ...
>>>> + Using 'conf at 0' configuration
>>>> + Trying 'fdt at 0' fdt subimage
>>>> + Description: Orangepi Win/Win+ Devicetree blob
>>>> + Type: Flat Device Tree
>>>> + Compression: uncompressed
>>>> + Data Start: 0x40710f24
>>>> + Data Size: 9032 Bytes = 8.8 KiB
>>>> + Architecture: AArch64
>>>> + Hash algo: sha256
>>>> + Hash value: ca3d874cd10466633ff133cc0156828d48c8efb96987fa45f885761d22a25dc1
>>>> + Verifying Hash Integrity ... sha256+ OK
>>>> + Booting using the fdt blob at 0x40710f24
>>>> + Uncompressing Kernel Image ... OK
>>>> + Loading Device Tree to 0000000049ffa000, end 0000000049fff347 ... OK
>>>> +
>>>> +Starting kernel ...
>>>> +---------------------------------------->8----------------------------------------
>>>> +
>>>> +Please pay attention to the lines that start with "Verifying Hash Integrity".
>>>> +
>>>> +"Verifying Hash Integrity ... sha256,rsa2048:dev+ OK" means the signature check
>>>> +passed.
>>>> +
>>>> +"Verifying Hash Integrity ... sha256+ OK" (2 times) means the hash check passed
>>>> +for kernel and DTB.
>>>> +
>>>> +If they are not displayed, the Verified Boot is not working.
>>>> +
>>>> +--
>>>> +Jagan Teki <jagan at amarulasolutions.com>
>>>> +13 Dec 2017
>>>>
>>>
>>> What's specific to sunxi boards in this README?
>>
>> it not board specific, it's generic sunxi platform README.
>
> I guess Quentin's point was that those instructions are generic to every
> U-Boot platform. There is nothing sunxi specific in there.
> docs/uImage.FIT is definitely the place for this doc to go.
Yeah, I understand instructions are generic for all platforms but what
I'm trying to show how these generic things are applying or verified
on sunxi like what other platforms does. (like README.unipher)
wouldn't be beneficial to show these details on sunxi?
thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.
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