126 lines
4.7 KiB
ArmAsm
126 lines
4.7 KiB
ArmAsm
/*
|
|
* \brief Transition between secure/normal worl
|
|
* \author Stefan Kalkowski
|
|
* \date 2015-02-16
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2015 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU General Public License version 2.
|
|
*/
|
|
|
|
/* core includes */
|
|
.include "macros.s"
|
|
|
|
/**
|
|
* Switch from nonsecure into secure world
|
|
*
|
|
* \param exception_type immediate exception type ID
|
|
* \param pc_adjust immediate value that gets subtracted from the
|
|
* vm's PC before it gets saved
|
|
*/
|
|
.macro _nonsecure_to_secure exception_type, pc_adjust
|
|
ldr sp, _tz_client_context /* load context pointer */
|
|
stmia sp, {r0-lr}^ /* save user regs r0-r12,sp,lr */
|
|
add r0, sp, #15*4
|
|
.if \pc_adjust != 0 /* adjust pc if necessary */
|
|
sub lr, lr, #\pc_adjust
|
|
.endif
|
|
stmia r0!, {lr} /* save pc */
|
|
mrs r1, spsr /* spsr to r0 */
|
|
mov r2, #\exception_type /* exception reason to r1 */
|
|
b _nonsecure_kernel_entry
|
|
.endm /* _non_to_secure */
|
|
|
|
|
|
/**
|
|
* Switch from secure into nonsecure world
|
|
*/
|
|
.macro _secure_to_nonsecure
|
|
ldr r0, _tz_client_context /* get vm context pointer */
|
|
add r0, r0, #18*4 /* add offset of banked modes */
|
|
_restore_bank 27 /* load undefined banks */
|
|
_restore_bank 19 /* load supervisor banks */
|
|
_restore_bank 23 /* load abort banks */
|
|
_restore_bank 18 /* load irq banks */
|
|
_restore_bank 17 /* load fiq banks */
|
|
ldmia r0!, {r8 - r12} /* load fiq r8-r12 */
|
|
cps #22 /* switch to monitor mode */
|
|
ldr sp, _tz_client_context /* get vm context pointer */
|
|
ldmia sp, {r0-lr}^ /* load user r0-r12,sp,lr */
|
|
ldr lr, [sp, #16*4] /* load vm's cpsr to lr */
|
|
msr spsr_cxfs, lr /* save cpsr to be load when switching */
|
|
mov lr, #13
|
|
mcr p15, 0, lr, c1, c1, 0 /* enable EA, FIQ, and NS bit in SCTRL */
|
|
ldr lr, [sp, #15*4] /* load vm's ip */
|
|
subs pc, lr, #0
|
|
.endm /* _secure_to_nonsecure */
|
|
|
|
|
|
.section .text
|
|
|
|
/* space for a copy of the kernel context */
|
|
.p2align 2
|
|
.global _tz_master_context
|
|
_tz_master_context:
|
|
.space 32 * 4
|
|
|
|
/* space for a client context-pointer */
|
|
.p2align 2
|
|
.global _tz_client_context
|
|
_tz_client_context:
|
|
.space CONTEXT_PTR_SIZE
|
|
|
|
_nonsecure_kernel_entry:
|
|
stmia r0!, {r1-r2} /* save spsr, and exception reason */
|
|
mrc p15, 0, r3, c6, c0, 0 /* move DFAR to r3 */
|
|
mrc p15, 0, r4, c2, c0, 0 /* move TTBR0 to r4 */
|
|
mrc p15, 0, r5, c2, c0, 1 /* move TTBR1 to r5 */
|
|
mrc p15, 0, r6, c2, c0, 2 /* move TTBRC to r6 */
|
|
mov r1, #0
|
|
mcr p15, 0, r1, c1, c1, 0 /* disable non-secure bit */
|
|
_save_bank 27 /* save undefined banks */
|
|
_save_bank 19 /* save supervisor banks */
|
|
_save_bank 23 /* save abort banks */
|
|
_save_bank 18 /* save irq banks */
|
|
_save_bank 17 /* save fiq banks */
|
|
stmia r0!, {r8-r12} /* save fiq r8-r12 */
|
|
stmia r0!, {r3-r6} /* save MMU registers */
|
|
cps #SVC_MODE
|
|
adr r0, _tz_master_context
|
|
_restore_kernel_sp r0, r1, r2 /* apply kernel sp */
|
|
add r1, r0, #LR_OFFSET
|
|
ldm r1, {lr, pc}
|
|
|
|
/* kernel must jump to this point to switch to a vm */
|
|
.global _mt_nonsecure_entry_pic
|
|
_mt_nonsecure_entry_pic:
|
|
_secure_to_nonsecure
|
|
|
|
/*
|
|
* On TrustZone exceptions the CPU has to jump to one of the following
|
|
* 7 entry vectors to switch to a kernel context.
|
|
*/
|
|
.p2align 5
|
|
.global _mon_kernel_entry
|
|
_mon_kernel_entry:
|
|
b _mon_rst_entry /* reset */
|
|
b _mon_und_entry /* undefined instruction */
|
|
b _mon_svc_entry /* supervisor call */
|
|
b _mon_pab_entry /* prefetch abort */
|
|
b _mon_dab_entry /* data abort */
|
|
nop /* reserved */
|
|
b _mon_irq_entry /* interrupt request */
|
|
_nonsecure_to_secure FIQ_TYPE, 4 /* fast interrupt request */
|
|
|
|
/* PICs that switch from a vm exception to the kernel */
|
|
_mon_rst_entry: _nonsecure_to_secure RST_TYPE, 0
|
|
_mon_und_entry: _nonsecure_to_secure UND_TYPE, 4
|
|
_mon_svc_entry: _nonsecure_to_secure SVC_TYPE, 0
|
|
_mon_pab_entry: _nonsecure_to_secure PAB_TYPE, 4
|
|
_mon_dab_entry: _nonsecure_to_secure DAB_TYPE, 8
|
|
_mon_irq_entry: _nonsecure_to_secure IRQ_TYPE, 4
|
|
|