RTOS/rtems
1
0
Fork 0
forked from Imagelibrary/rtems
Code Pull Requests Activity

bsps/arm: Move HYP to SVC change to start.S

Browse Source 
This fixes the corruption of r3 by the call to
bsp_start_arm_drop_hyp_mode().

Moving the code makes it easier to review changes in start.S.

Close #3773.
This commit is contained in:
Sebastian Huber
2019-07-26 08:12:20 +02:00
parent 0ee2125a92
commit 1e6380baf2
3 changed files with 40 additions and 81 deletions
Download Patch File Download Diff File Expand all files Collapse all files

76
bsps/arm/shared/start/bsp-start-in-hyp-support.S
View File

@@ -1,76 +0,0 @@
/**
* @file
*
* @brief Boot and system start code.
*/
/*
* Copyright (c) 2016 Pavel Pisa <pisa@cmp.felk.cvut.cz>
*
* Czech Technical University in Prague
* Zikova 1903/4
* 166 36 Praha 6
* Czech Republic
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#include <rtems/asm.h>
#include <rtems/score/cpu.h>
#include <bspopts.h>
#include <bsp/irq.h>
#include <bsp/linker-symbols.h>
.extern bsp_start_hyp_vector_table_begin
.globl bsp_start_arm_drop_hyp_mode
.globl bsp_arm_drop_hyp_mode_only
.arm
/*
* The routine is called from startup code and it should
* preserve all registers except r2 and r3. r0 can be used
* as pass though argument in some cases, a1 is used for
* CPU stack offset during startup and r4 to r6 to preserve
* booloader arguments
*/
bsp_start_arm_drop_hyp_mode:
ldr r2, bsp_start_hyp_vector_table_begin_addr
mcr p15, 4, r2, c12, c0, 0
mov r2, #0
mcr p15, 4, r2, c1, c1, 0
mcr p15, 4, r2, c1, c1, 2
mcr p15, 4, r2, c1, c1, 3
/*
* HSCTLR.TE
* optional start of hypervisor handlers in Thumb mode
* orr r0, #(1 << 30)
*/
mcr p15, 4, r2, c1, c0, 0 /* HSCTLR */
mrc p15, 4, r2, c1, c1, 1 /* HDCR */
and r2, #0x1f /* Preserve HPMN */
mcr p15, 4, r2, c1, c1, 1 /* HDCR */
bsp_arm_drop_hyp_mode_only:
/* Prepare SVC mode for eret */
mrs r2, cpsr
bic r2, r2, #ARM_PSR_M_MASK
orr r2, r2, #ARM_PSR_M_SVC
msr spsr_cxsf, r2
adr r2, 1f
.inst 0xe12ef302 /* msr ELR_hyp, r2 */
mov r2, sp
mov r3, lr
.inst 0xe160006e /* eret */
1: mov sp, r2
mov lr, r3
bx lr
bsp_start_hyp_vector_table_begin_addr:
.word bsp_start_hyp_vector_table_begin

42
bsps/arm/shared/start/start.S
View File

@@ -13,6 +13,13 @@
* Germany
* <rtems@embedded-brains.de>
*
* Copyright (c) 2016 Pavel Pisa <pisa@cmp.felk.cvut.cz>
*
* Czech Technical University in Prague
* Zikova 1903/4
* 166 36 Praha 6
* Czech Republic
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
@@ -200,13 +207,44 @@ _start:
bne .L_skip_hyp_svc_switch
/* Boot loader starts kernel in HYP mode, switch to SVC necessary */
ldr r1, =bsp_stack_hyp_size
mov sp, r3
sub r3, r3, r1
bl bsp_start_arm_drop_hyp_mode
ldr r2, =bsp_start_hyp_vector_table_begin
mcr p15, 4, r2, c12, c0, 0
mov r2, #0
mcr p15, 4, r2, c1, c1, 0
mcr p15, 4, r2, c1, c1, 2
mcr p15, 4, r2, c1, c1, 3
/*
* HSCTLR.TE
* optional start of hypervisor handlers in Thumb mode
* orr r0, #(1 << 30)
*/
mcr p15, 4, r2, c1, c0, 0 /* HSCTLR */
mrc p15, 4, r2, c1, c1, 1 /* HDCR */
and r2, #0x1f /* Preserve HPMN */
mcr p15, 4, r2, c1, c1, 1 /* HDCR */
/* Prepare SVC mode for eret */
mrs r2, cpsr
bic r2, r2, #ARM_PSR_M_MASK
orr r2, r2, #ARM_PSR_M_SVC
msr spsr_cxsf, r2
adr r2, .L_hyp_to_svc_return
.inst 0xe12ef302 /* msr ELR_hyp, r2 */
mov r2, sp
.inst 0xe160006e /* eret */
.L_hyp_to_svc_return:
mov sp, r2
.L_skip_hyp_svc_switch:
#endif
#endif /* BSP_START_IN_HYP_SUPPORT */
/* Initialize stack pointer registers for the various modes */
/* Enter FIQ mode and set up the FIQ stack pointer */

3
c/src/lib/libbsp/arm/raspberrypi/Makefile.am
View File

@@ -45,9 +45,6 @@ librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/start/sbrk.c
librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/start/stackalloc.c
librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/shared/start/bsp-start-memcpy.S
librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/shared/cp15/arm-cp15-set-ttb-entries.c
if BSP_START_IN_HYP_SUPPORT
librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/shared/start/bsp-start-in-hyp-support.S
endif
# Startup
librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/raspberrypi/start/bspstart.c