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.martin@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
-
Dave Martin