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 >> ?