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. --- bsps/arm/shared/start/bsp-start-in-hyp-support.S | 76 ------------------------ bsps/arm/shared/start/start.S | 42 ++++++++++++- c/src/lib/libbsp/arm/raspberrypi/Makefile.am | 3 - 3 files changed, 40 insertions(+), 81 deletions(-) delete mode 100644 bsps/arm/shared/start/bsp-start-in-hyp-support.S diff --git a/bsps/arm/shared/start/bsp-start-in-hyp-support.S b/bsps/arm/shared/start/bsp-start-in-hyp-support.S deleted file mode 100644 index 5d3d5921c5..0000000000 --- a/bsps/arm/shared/start/bsp-start-in-hyp-support.S +++ /dev/null @@ -1,76 +0,0 @@ -/** - * @file - * - * @brief Boot and system start code. - */ - - /* - * Copyright (c) 2016 Pavel Pisa <p...@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 diff --git a/bsps/arm/shared/start/start.S b/bsps/arm/shared/start/start.S index 1f6d38f564..0e9e6a0cde 100644 --- a/bsps/arm/shared/start/start.S +++ b/bsps/arm/shared/start/start.S @@ -13,6 +13,13 @@ * Germany * <rt...@embedded-brains.de> * + * Copyright (c) 2016 Pavel Pisa <p...@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 */ diff --git a/c/src/lib/libbsp/arm/raspberrypi/Makefile.am b/c/src/lib/libbsp/arm/raspberrypi/Makefile.am index 14a348411d..11a22f89e3 100644 --- a/c/src/lib/libbsp/arm/raspberrypi/Makefile.am +++ b/c/src/lib/libbsp/arm/raspberrypi/Makefile.am @@ -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 -- 2.16.4 _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
