[U-Boot] [PATCH v2 11/12] tegra124: Reserve secure RAM using MC_SECURITY_CFG{0, 1}_0

Stephen Warren
2015-02-17T21:06:55Z

On 02/16/2015 05:54 AM, Jan Kiszka wrote:
> From: Ian Campbell <ijc@hellion.org.uk>
>
> These registers can be used to prevent non-secure world from accessing a
> megabyte aligned region of RAM, use them to protect the u-boot secure monitor
> code.
>
> At first I tried to do this from s_init(), however this inexplicably causes
> u-boot's networking (e.g. DHCP) to fail, while networking under Linux was fine.
>
> So instead I have added a new weak arch function protect_secure_section()
> called from relocate_secure_section() and reserved the region there. This is
> better overall since it defers the reservation until after the sec vs. non-sec
> decision (which can be influenced by an envvar) has been made when booting the
> os.

> diff --git a/arch/arm/cpu/tegra-common/ap.c b/arch/arm/cpu/tegra-common/ap.c

> +void protect_secure_section(void)

> + writel(CONFIG_ARMV7_SECURE_BASE, &mc->mc_security_cfg0);
> + writel(CONFIG_ARMV7_SECURE_RESERVE_SIZE>>20, &mc->mc_security_cfg1);

Spaces around the >> ?