Currently, the bootwrapper switches unconditionally to NS Hyp mode,
which prevents successful execution of a kernel which expects to
start in the Secure world.
This patch adds a --secure command-line option to enable Secure
world booting.
NS HYP remains the default.
Signed-off-by: Dave Martin <dave.mar...@linaro.org>
---
Note that this is just an RFC -- I've not tested it yet.
With some additional CCI and CPU reset related hacks, I hope to get the
in-kernel switcher kernel booting with this.
boot.S | 36 ++++++++++++++++++++++++++++--------
boot.h | 29 +++++++++++++++++++++++++++++
semi_loader.c | 11 +++++++++++
3 files changed, 68 insertions(+), 8 deletions(-)
create mode 100644 boot.h
diff --git a/boot.S b/boot.S
index 727119a..64cd0fa 100644
--- a/boot.S
+++ b/boot.S
@@ -7,18 +7,28 @@
* found in the LICENSE.txt file.
*/
+#include "boot.h"
+
.syntax unified
.arch_extension sec
.arch_extension virt
.text
-.macro enter_hyp
- @ We assume we're entered in Secure Supervisor mode. To
- @ get to Hyp mode we have to pass through Monitor mode
- @ and NS-Supervisor mode. Note that there is no way to
- @ return to the Secure world once we've done this.
- @
+.macro enter_kernel_state
@ This will trash r10 and r11.
+ @ We assume we're entered in Secure Supervisor mode.
+
+ @ If requested, stay in Secure SVC to enter the kernel:
+
+ ldr r10, =kernel_boot_mode
+ ldr r10, [r10]
+ cmp r10, #BOOT_MODE_S_SVC
+ beq 1f
+
+ @ Otherwise: to get to Hyp mode we have to pass through Monitor
+ @ mode and NS-Supervisor mode. Note that there is no way to
+ @ return to the Secure world once we've done this.
+
ldr r10, =vectors
mcr p15, 0, r10, c12, c0, 1 @ Monitor vector base address
@ Switch to monitor mode, which will set up the HVBAR and
@@ -26,7 +36,9 @@
smc #0
@ Now we're in NS-SVC, make a Hyp call to get into Hyp mode
hvc #0
+
@ We will end up here in NS-Hyp.
+1:
.endm
.align 5
@@ -128,7 +140,7 @@ start:
@
@ Secondary CPUs (following the RealView SMP booting protocol)
@
- enter_hyp
+ enter_kernel_state
ldr r1, =fs_start - 0x100
adr r2, 1f
@@ -198,7 +210,7 @@ __boot_kernel:
stmfd sp!, {r1-r3}
ldmia sp, {r0-r3}
- enter_hyp
+ enter_kernel_state
bx r4
.type __boot_kernel, %function
@@ -214,3 +226,11 @@ kernel_cmd:
.asciz KCMD
#endif
kernel_cmd_end:
+
+
+.bss
+.align 2
+
+.globl kernel_boot_mode
+kernel_boot_mode:
+ .skip 4 @ defaults to BOOT_MODE_NS_HYP (0)
diff --git a/boot.h b/boot.h
new file mode 100644
index 0000000..b80227e
--- /dev/null
+++ b/boot.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2012 Linaro Limited
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name of Linaro Limited nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ */
+
+#ifndef BOOT_H
+#define BOOT_H
+
+#define BOOT_MODE_NS_HYP 0
+#define BOOT_MODE_S_SVC 1
+
+#ifndef __ASSEMBLER__
+extern int kernel_boot_mode;
+#endif /* ! __ASSEMBLER__ */
+
+#endif /* BOOT_H */
diff --git a/semi_loader.c b/semi_loader.c
index cbe911c..ef927e7 100644
--- a/semi_loader.c
+++ b/semi_loader.c
@@ -17,6 +17,7 @@
*/
#include <string.h>
+#include "boot.h"
#include "libfdt.h"
#include "semihosting.h"
#include "semi_loader.h"
@@ -49,6 +50,7 @@ static void _print_info(char const **strings)
#define CMDLINE_NOINITRD "--no-initrd"
#define CMDLINE_DTB "--dtb"
#define CMDLINE_FDT "--fdt" /* deprecated */
+#define CMDLINE_SECURE "--secure"
#define CMDLINE_REST "-- "
static void _usage_fatal(void)
@@ -378,6 +380,7 @@ static char *fdt_arg = (void *)0;
static char *dtb_arg = (void *)0;
static char *cmdline_arg = (void *)0;
static char *noinitrd_arg = (void *)0;
+static char *secure_arg = (void *)0;
static const struct {
char const *option_string;
@@ -389,6 +392,7 @@ static const struct {
{ CMDLINE_NOINITRD, &noinitrd_arg, OPT_BOOL },
{ CMDLINE_FDT, &fdt_arg, OPT_ARG },
{ CMDLINE_DTB, &dtb_arg, OPT_ARG },
+ { CMDLINE_SECURE, &secure_arg, OPT_BOOL },
{ CMDLINE_REST, &cmdline_arg, OPT_REST },
};
@@ -476,6 +480,13 @@ args_done:
dtb_arg = fdt_arg;
}
+ info("Kernel will be booted in ");
+ if(secure_arg) {
+ kernel_boot_mode = BOOT_MODE_S_SVC;
+ info("Secure SVC mode.\n");
+ } else
+ info("HYP mode.\n");
+
/*
* Now, proceed to load images and set up ATAGs.
* For simplicity, ATAGs are generated even if there is a DTB
--
1.7.4.1
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