ARM: HYP/non-sec: allow relocation to secure RAM

The current non-sec switching code suffers from one major issue:
it cannot run in secure RAM, as a large part of u-boot still needs
to be run while we're switched to non-secure.

This patch reworks the whole HYP/non-secure strategy by:
- making sure the secure code is the *last* thing u-boot executes
  before entering the payload
- performing an exception return from secure mode directly into
  the payload
- allowing the code to be dynamically relocated to secure RAM
  before switching to non-secure.

This involves quite a bit of horrible code, specially as u-boot
relocation is quite primitive.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/arm/include/asm/secure.h b/arch/arm/include/asm/secure.h
new file mode 100644
index 0000000000..effdb1858d
--- /dev/null
+++ b/arch/arm/include/asm/secure.h
@@ -0,0 +1,26 @@
+#ifndef __ASM_SECURE_H
+#define __ASM_SECURE_H
+
+#include <config.h>
+
+#ifdef CONFIG_ARMV7_SECURE_BASE
+/*
+ * Warning, horror ahead.
+ *
+ * The target code lives in our "secure ram", but u-boot doesn't know
+ * that, and has blindly added reloc_off to every relocation
+ * entry. Gahh. Do the opposite conversion. This hack also prevents
+ * GCC from generating code veeners, which u-boot doesn't relocate at
+ * all...
+ */
+#define secure_ram_addr(_fn) ({						\
+			DECLARE_GLOBAL_DATA_PTR;			\
+			void *__fn = _fn;				\
+			typeof(_fn) *__tmp = (__fn - gd->reloc_off);	\
+			__tmp;						\
+		})
+#else
+#define secure_ram_addr(_fn)	(_fn)
+#endif
+
+#endif