[U-Boot] u-boot on raspberry 2: booting in SVC secure mode

[Vincent]

Thank to your last email, I finally managed to boot in secure mode with
(what I consider as) minimal changes:
- kernel_old=1
- CONFIG_SYS_TEXT_BASE=0
- halting other cores in start.S:reset
- commenting away line 113 in arch/arm/cpu/armv7/virt-v7.c:
smp_set_core_boot_addr((unsigned long)secure_ram_addr(_smp_pen), -1);
- hack around _smp_pen so the code compiles correctly
- adding two defines to rpi_2.h
  #define CONFIG_ARMV7_NONSEC
  #define CONFIG_ARMV7_BOOT_SEC_DEFAULT

I'm uploading this fork on github (https://github.com/vsiles/u-boot) if
anyone is interested. I'm pretty sure that not the "right" way to do it,
but it works for now :)
Thank you very much for your help
V.

2015-02-28 5:58 GMT+01:00 Stephen Warren <swarren at wwwdotorg.org>:

> On 02/26/2015 02:32 AM, Vincent wrote:
> > I tried what Stephen suggested, and just changing CONFIG_SYS_TEXT_BASE
> > to 0x0 (with kernel_old=1) does not work: the board display some garbage
> > on the uart then hangs. The content of the garbage makes me thinks that
> > nothing is done to handle the four cores in this setting which ends up
> > badly. I expected this since raspberry's "firmware" only let one core
> > run free. I think I need to configure U-boot so that it deals with this
> > SMP scenario (I just don't know how).
>
> That expectation seems correct! I hacked in some code right at the start
> of U-Boot (reset: in arch/arm/cpu/armv7/start.S) that extracted the
> CPUID from the MPIDR register, and only allowed CPU0 to continue. With
> that in place, kernel_old=1 and CONFIG_SYS_TEXT_BASE=0 worked.
>
> Interesting that all CPU cores get released at reset; the other SoCs
> I've used only release CPU0 and you have to explicitly boot CPUn.
>
> > My goal is to use U-boot to load some small homemade baremetal kernels
> > on the raspberry (using serial or tftp loading), in *secure mode*, so I
> > need U-boot to stay in secure mode, or at least let me install my own
> > secure_monitor code before switching to non-secure mode.
> >
> > I made a couple attempts of adding secure mode support by adding options
> > in configs/rpi_2_defconfig but they don't seem to be taken into account.
> > Where do you suggest I put ARMV7_virt and ARMV7_NONSEC ?
>
> I would suggest adding #defines to include/configs/rpi_2.h.
>