[U-Boot] [PATCH 03/11] spl: Add FIT boot into OP-TEE then U-Boot proper

Sat Jul 14 00:11:47 UTC 2018

From: Henry Beberman <henry.beberman at microsoft.com>

This patch is a part of the i.MX Windows 10 IoT Core boot flow.

It adds an entry path for OP-TEE when loaded from a FIT blob when
loadable has the OS type IH_OS_TEE. This booth path flushes and
disables caches, disables interrupts, and jumps into OP-TEE passing
the entry point for U-Boot Proper in one of the registers.

The CONFIG_SPL_OPTEE_BOOT option enables this boot path, and is also
used to automatically set the CONFIG_SYS_NORMAL_WORLD Kconfig option
while building U-Boot proper. This is because when OP-TEE returns to
U-Boot proper's entry point, it will be in normal mode, so several
secure world only initializations need to be omitted.

New Kconfig option:
CONFIG_SPL_OPTEE_BOOT - Enables SPL FIT to boot in to OP-TEE, and will
set the CONFIG_SYS_NORMAL_WORLD in U-Boot Proper to omit secure world
only code.

Signed-off-by: Henry Beberman <henry.beberman at microsoft.com>
Cc: Stefano Babic <sbabic at denx.de>
Cc: Fabio Estevam <fabio.estevam at nxp.com>
Cc: Tom Rini <trini at konsulko.com>
---
 arch/arm/cpu/armv7/Makefile     |  1 +
 arch/arm/cpu/armv7/optee_jump.S | 31 +++++++++++++++++++++++++++++++
 arch/arm/lib/spl.c              | 16 ++++++++++++++++
 common/spl/Kconfig              |  9 +++++++++
 common/spl/spl.c                |  6 ++++++
 include/spl.h                   | 21 +++++++++++++++++++++
 6 files changed, 84 insertions(+)
 create mode 100644 arch/arm/cpu/armv7/optee_jump.S

diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 4f4647c90a..5bad36a8b8 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/arch/arm/cpu/armv7/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_ARMV7_PSCI)	+= psci.o psci-common.o
 obj-$(CONFIG_IPROC) += iproc-common/
 obj-$(CONFIG_KONA) += kona-common/
 obj-$(CONFIG_SYS_ARCH_TIMER) += arch_timer.o
+obj-$(CONFIG_SPL_OPTEE_BOOT) += optee_jump.o
 
 ifneq (,$(filter s5pc1xx exynos,$(SOC)))
 obj-y += s5p-common/
diff --git a/arch/arm/cpu/armv7/optee_jump.S b/arch/arm/cpu/armv7/optee_jump.S
new file mode 100644
index 0000000000..2a1d994bcc
--- /dev/null
+++ b/arch/arm/cpu/armv7/optee_jump.S
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 Microsoft Corporation
+ */
+
+#include <asm-offsets.h>
+#include <config.h>
+#include <asm/system.h>
+#include <linux/linkage.h>
+
+#ifdef CONFIG_SPL_OPTEE_BOOT
+
+	.globl arch_jump_to_image_optee
+
+/*
+ void __noreturn arch_jump_to_image_optee(
+	u32 optee_entry_point,
+	u32 pageable_part,
+	u32 uboot_entry_point
+	);
+*/
+ENTRY(arch_jump_to_image_optee)
+
+	mov r3, r0
+	mov r0, r1
+	mov lr, r2
+
+	bx r3
+
+ENDPROC(arch_jump_to_image_optee)
+#endif
diff --git a/arch/arm/lib/spl.c b/arch/arm/lib/spl.c
index 33cc76ba3d..ee311d9fe8 100644
--- a/arch/arm/lib/spl.c
+++ b/arch/arm/lib/spl.c
@@ -73,3 +73,19 @@ void __noreturn jump_to_image_linux(struct spl_image_info *spl_image)
 }
 #endif	/* CONFIG_ARM64 */
 #endif
+
+#ifdef CONFIG_SPL_OPTEE_BOOT
+void __noreturn arch_jump_to_image_optee(u32 optee_entry_point,
+					 u32 pageable_part,
+					 u32 uboot_entry_point);
+
+void __noreturn jump_to_image_optee(struct spl_image_info *spl_image)
+{
+	/* flush and turn off caches before jumping to OPTEE */
+	cleanup_before_linux();
+
+	arch_jump_to_image_optee(spl_image->entry_point,
+				 0,
+				 CONFIG_SYS_TEXT_BASE);
+}
+#endif
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 0bbf8d5b02..643484a4a4 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -792,6 +792,15 @@ config SPL_ATF_NO_PLATFORM_PARAM
 
 	  If your ATF is affected, say Y.
 
+config SPL_OPTEE_BOOT
+	depends on SPL
+	bool "Enable support for loading OPTEE and jumping to it from SPL"
+	default n
+	help
+	  Configure SPL to boot OPTEE. SPL passes the U-Boot proper entry
+	  point as the return address when it jumps to OPTEE, allowing OPTEE
+	  to start U-Boot proper in normal mode when it returns.
+
 config SPL_AM33XX_ENABLE_RTC32K_OSC
 	bool "Enable the RTC32K OSC on AM33xx based platforms"
 	default y if AM33XX
diff --git a/common/spl/spl.c b/common/spl/spl.c
index a09ada37d7..237083b08d 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -519,6 +519,12 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
 		spl_invoke_atf(&spl_image);
 		break;
 #endif
+#ifdef CONFIG_SPL_OPTEE_BOOT
+	case IH_OS_TEE:
+		debug("Jumping to OPTEE\n");
+		jump_to_image_optee(&spl_image);
+		break;
+#endif
 #ifdef CONFIG_SPL_OS_BOOT
 	case IH_OS_LINUX:
 		debug("Jumping to Linux\n");
diff --git a/include/spl.h b/include/spl.h
index 8454ea7ad4..338b4b573d 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -125,6 +125,19 @@ int spl_board_ubi_load_image(u32 boot_device);
  */
 void __noreturn jump_to_image_linux(struct spl_image_info *spl_image);
 
+#ifdef CONFIG_SPL_OPTEE_BOOT
+/**
+ * jump_to_image_optee() - Jump to OP-TEE from SPL
+ *
+ * This jumps into OP-TEE using the information in @spl_image, passing
+ *  it the entry point of U-Boot Proper so it can return there
+ *  in non-secure mode
+ *
+ * @spl_image: Image description to set up
+ */
+void __noreturn jump_to_image_optee(struct spl_image_info *spl_image);
+#endif
+
 /**
  * spl_start_uboot() - Check if SPL should start the kernel or U-Boot
  *
@@ -296,4 +309,12 @@ void spl_invoke_atf(struct spl_image_info *spl_image);
  * can implement 'board_return_to_bootrom'.
  */
 void board_return_to_bootrom(void);
+
+#ifdef CONFIG_SPL_OPTEE_BOOT
+#include <tee/optee.h>
+
+struct optee_image_info {
+	struct optee_header header;
+};
+#endif
 #endif
-- 
2.16.2.gvfs.1.33.gf5370f1

