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>

2 files changed, 33 insertions, 3 deletions

diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h
index 395444e..11476dd 100644
--- a/arch/arm/include/asm/armv7.h
+++ b/arch/arm/include/asm/armv7.h
@@ -78,13 +78,17 @@ void v7_outer_cache_inval_range(u32 start, u32 end);
 
 #if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
 
-int armv7_switch_nonsec(void);
-int armv7_switch_hyp(void);
+int armv7_init_nonsec(void);
 
 /* defined in assembly file */
 unsigned int _nonsec_init(void);
+void _do_nonsec_entry(void *target_pc, unsigned long r0,
+		      unsigned long r1, unsigned long r2);
 void _smp_pen(void);
-void _switch_to_hyp(void);
+
+extern char __secure_start[];
+extern char __secure_end[];
+
 #endif /* CONFIG_ARMV7_NONSEC || CONFIG_ARMV7_VIRT */
 
 #endif /* ! __ASSEMBLY__ */
diff --git a/arch/arm/include/asm/secure.h b/arch/arm/include/asm/secure.h
new file mode 100644
index 0000000..effdb18
--- /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