Hi Sean,
On Fri, 11 Aug 2023 at 11:14, Sean Edmond seanedmond@linux.microsoft.com wrote:
On 2023-08-09 6:49 p.m., Simon Glass wrote:
Hi Sean,
On Wed, 9 Aug 2023 at 16:35, Sean Edmond seanedmond@linux.microsoft.com
wrote:
On 2023-08-08 7:03 p.m., Simon Glass wrote:
Hi,
On Fri, 4 Aug 2023 at 17:34, seanedmond@linux.microsoft.com wrote:
From: Dhananjay Phadke dphadke@linux.microsoft.com
fdt_fixup_kaslr_seed() will update given FDT with random seed value. Source for random seed can be TPM or RNG driver in u-boot or sec firmware (ARM).
Signed-off-by: Dhananjay Phadke dphadke@linux.microsoft.com
arch/arm/cpu/armv8/sec_firmware.c | 32
+++++++------------------------
common/fdt_support.c | 31
++++++++++++++++++++++++++++++
include/fdt_support.h | 3 +++ 3 files changed, 41 insertions(+), 25 deletions(-)
We need to find a way to use the ofnode API here.
diff --git a/arch/arm/cpu/armv8/sec_firmware.c
b/arch/arm/cpu/armv8/sec_firmware.c
index c0e8726346..84ba49924e 100644 --- a/arch/arm/cpu/armv8/sec_firmware.c +++ b/arch/arm/cpu/armv8/sec_firmware.c @@ -411,46 +411,28 @@ int sec_firmware_init(const void
*sec_firmware_img,
/* * fdt_fix_kaslr - Add kalsr-seed node in Device tree * @fdt: Device tree
- @eret: 0 in case of error, 1 for success
int fdt_fixup_kaslr(void *fdt)
- @eret: 0 for success */
You could pass an oftree to this function, e.g. obtained with:
oftree_from_fdt(fdt)
The common API I added is fdt_fixup_kaslr_seed(), which was added to "common/fdt_support.c".
There are 3 callers: sec_firmware_init()->fdt_fixup_kaslr_seed() do_kaslr_seed()->fdt_fixup_kaslr_seed() image_setup_libfdt()->fdt_tpm_kaslr_seed->fdt_fixup_kaslr_seed()
I think the ask is to create a common API that uses the ofnode API.
So,
instead of fdt_fixup_kaslr_seed() I can create ofnode_fixup_kaslr_seed()? Where should it live?
If you like you could add common/ofnode_support.c ?
But it is OK to have it in the same file, I think.
Are you also wanting the callers (eg. fdt_tpm_kaslr_seed, fdt_fixup_kaslr) to take oftree as input too?
So far as you can go, yes. Also you may want to pass an ofnode (the root node) so that things can deal with adding their stuff to any node.
Regards, Simon
I re-worked the API to use the ofnode API and tested it on our board. I was required to explicitly enable CONFIG_OFNODE_MULTI_TREE in order for it to work.
I have concerns this will create a breaking change for users of the kaslr fdt touch up. In our case, if CONFIG_OFNODE_MULTI_TREE isn't set, the control FDT gets touched up, not the kernel FDT as required. Everything runs to completion, but "/proc/device-tree/chosen/kaslr-seed" isn't present after boot.
Am I missing something? Perhaps there's a way to modify the default value for CONFIG_OFNODE_MULTI_TREE to ensure this works out-of-the-box?
Yes, perhaps we should enable this when fixups are used? Is there a way to tell?
Also, we should make it return an error when attempting to use a tree without that option enabled. I would expect oftree_ensure() to provide that?
Regards, Simon