[U-Boot] [PATCH] ARM: bootm: Allow booting in secure mode on hyp capable systems

[Marc Zyngier <marc.zyngier@arm.com>]

On Wed, Oct 15 2014 at 11:40:24 AM, Siarhei Siamashka <siarhei.siamashka@gmail.com> wrote:
> On Wed, 15 Oct 2014 11:31:44 +0100
> Marc Zyngier <marc.zyngier@arm.com> wrote:
>
>> On Wed, Oct 15 2014 at 11:25:10 AM, Siarhei Siamashka
>> <siarhei.siamashka@gmail.com> wrote:
>> > On Wed, 15 Oct 2014 12:13:05 +0200
>> > Hans de Goede <hdegoede@redhat.com> wrote:
>> >
>> >> Older Linux kernels will not properly boot in hype mode, add support for a
>> >> bootm_boot_mode environment variable, which when set to "sec" will cause
>> >> u-boot to boot in secure mode even when build with non-sec (and hyp) support.
>> >> 
>> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> >> ---
>> >>  arch/arm/lib/bootm.c | 23 ++++++++++++++++++-----
>> >>  1 file changed, 18 insertions(+), 5 deletions(-)
>> >> 
>> >> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
>> >> index 39fe7a1..037fc8d 100644
>> >> --- a/arch/arm/lib/bootm.c
>> >> +++ b/arch/arm/lib/bootm.c
>> >> @@ -235,6 +235,18 @@ static void boot_prep_linux(bootm_headers_t *images)
>> >>  	}
>> >>  }
>> >>  
>> >> +#if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
>> >> +static bool boot_nonsec(void)
>> >> +{
>> >> +	char *s = getenv("bootm_boot_mode");
>> >> +
>> >> +	if (s && !strcmp(s, "sec"))
>> >> +		return false;
>> >> +
>> >> +	return true;
>> >> +}
>> >> +#endif
>> >> +
>> >>  /* Subcommand: GO */
>> >>  static void boot_jump_linux(bootm_headers_t *images, int flag)
>> >>  {
>> >> @@ -283,12 +295,13 @@ static void boot_jump_linux(bootm_headers_t *images, int flag)
>> >>  
>> >>  	if (!fake) {
>> >>  #if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
>> >> -		armv7_init_nonsec();
>> >> -		secure_ram_addr(_do_nonsec_entry)(kernel_entry,
>> >> -						  0, machid, r2);
>> >> -#else
>> >> -		kernel_entry(0, machid, r2);
>> >> +		if (boot_nonsec()) {
>> >> +			armv7_init_nonsec();
>> >> +			secure_ram_addr(_do_nonsec_entry)(kernel_entry,
>> >> +							  0, machid, r2);
>> >> +		}
>> >>  #endif
>> >> +		kernel_entry(0, machid, r2);
>> >>  	}
>> >>  #endif
>> >>  }
>> >
>> > BTW, I'm currently achieving the same result, but without the need to do
>> > extra environment configuration gymnastics for the end users:
>> >     https://github.com/ssvb/u-boot-sunxi-dram/commit/e914abe551e712a59a8fc1ac9a4b8490e8e7c866
>> 
>> And thus preventing kernels with appended DT (not provided by u-boot),
>> but still using HYP/non-sec/PSCI from booting.
>> 
>> Sorry, but using DT as a way to distinguish between all these cases is
>> just wrong.
>> 
>> Thanks,
>
> Do you see the HACK prefix in the summary of that patch?

I do. But the fact that you even mention it here makes me think that you
believe it is a better approach that Hans'.

> Or are you saying that it is really impossible to distinguish your
> use case of having the appended DT without resorting to the use of the
> environment config options?

Think of it. How do you find out about what the kernel wants? This is
just a blob...

	M.
-- 
Jazz is not dead. It just smells funny.