[PATCH 05/13] bsps/arm: Set VBAR in start.S

Sebastian Huber sebastian.huber at embedded-brains.de
Tue Dec 22 13:01:02 UTC 2020


Set the VBAR to the vector table in the start section before
bsp_start_hook_0() is called to ealier handle exceptions in RTEMS.

Set the VBAR to the normal vector table in start.S for the main
processor.  Secondary processors set it in bsp_start_hook_0().

Update #4202.
---
 bsps/arm/beagle/start/bspstarthooks.c        |  4 --
 bsps/arm/headers.am                          |  1 -
 bsps/arm/imx/start/bspstarthooks.c           |  1 -
 bsps/arm/include/bsp/arm-a8core-start.h      | 55 --------------------
 bsps/arm/include/bsp/arm-a9mpcore-start.h    | 27 ++--------
 bsps/arm/raspberrypi/start/bspsmp_init.c     |  3 ++
 bsps/arm/raspberrypi/start/bspstarthooks.c   |  3 --
 bsps/arm/shared/start/start.S                | 28 +++++++++-
 bsps/arm/xen/start/bspstarthooks.c           |  2 -
 bsps/arm/xilinx-zynqmp/start/bspstarthooks.c |  2 -
 spec/build/bsps/arm/grp.yml                  |  1 -
 11 files changed, 33 insertions(+), 94 deletions(-)
 delete mode 100644 bsps/arm/include/bsp/arm-a8core-start.h

diff --git a/bsps/arm/beagle/start/bspstarthooks.c b/bsps/arm/beagle/start/bspstarthooks.c
index 2efa3042a8..38f2903d4d 100644
--- a/bsps/arm/beagle/start/bspstarthooks.c
+++ b/bsps/arm/beagle/start/bspstarthooks.c
@@ -15,9 +15,6 @@
 #include <bsp.h>
 #include <bsp/start.h>
 #include <bsp/arm-cp15-start.h>
-#include <bsp/arm-a8core-start.h>
-
-#include <bsp/uart-output-char.h>
 
 BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 {
@@ -25,7 +22,6 @@ BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 
 BSP_START_TEXT_SECTION void bsp_start_hook_1(void)
 {
-  arm_a8core_start_hook_1();
   bsp_start_copy_sections();
   beagle_setup_mmu_and_cache();
   bsp_start_clear_bss();
diff --git a/bsps/arm/headers.am b/bsps/arm/headers.am
index a4d6dfa09e..92af7e1059 100644
--- a/bsps/arm/headers.am
+++ b/bsps/arm/headers.am
@@ -10,7 +10,6 @@ include_HEADERS += ../../../../../bsps/arm/include/uart.h
 
 include_bspdir = $(includedir)/bsp
 include_bsp_HEADERS =
-include_bsp_HEADERS += ../../../../../bsps/arm/include/bsp/arm-a8core-start.h
 include_bsp_HEADERS += ../../../../../bsps/arm/include/bsp/arm-a9mpcore-clock.h
 include_bsp_HEADERS += ../../../../../bsps/arm/include/bsp/arm-a9mpcore-irq.h
 include_bsp_HEADERS += ../../../../../bsps/arm/include/bsp/arm-a9mpcore-regs.h
diff --git a/bsps/arm/imx/start/bspstarthooks.c b/bsps/arm/imx/start/bspstarthooks.c
index d35374e360..f2ea7b4863 100644
--- a/bsps/arm/imx/start/bspstarthooks.c
+++ b/bsps/arm/imx/start/bspstarthooks.c
@@ -102,7 +102,6 @@ BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 
 BSP_START_TEXT_SECTION void bsp_start_hook_1(void)
 {
-  arm_a9mpcore_start_set_vector_base();
   bsp_start_copy_sections();
   setup_mmu_and_cache();
   bsp_start_clear_bss();
diff --git a/bsps/arm/include/bsp/arm-a8core-start.h b/bsps/arm/include/bsp/arm-a8core-start.h
deleted file mode 100644
index d9b7274018..0000000000
--- a/bsps/arm/include/bsp/arm-a8core-start.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/**
- *  @file
- *
- *  @ingroup RTEMSBSPsARMShared
- *
- *  @brief A8CORE_START Support
- */
-
-/*
- * Copyright (c) 2014 Chris Johns <chrisj at rtems.org>.  All rights reserved.
- *
- * 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.
- */
-
-#ifndef LIBBSP_ARM_SHARED_ARM_A8CORE_START_H
-#define LIBBSP_ARM_SHARED_ARM_A8CORE_START_H
-
-#include <libcpu/arm-cp15.h>
-
-#include <bsp.h>
-#include <bsp/start.h>
-#include <bsp/arm-errata.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
-BSP_START_TEXT_SECTION static inline void arm_a8core_start_set_vector_base(void)
-{
-  /*
-   * Do not use bsp_vector_table_begin == 0, since this will get optimized away.
-  */
-  if (bsp_vector_table_end != bsp_vector_table_size) {
-    uint32_t ctrl;
-
-    arm_cp15_set_vector_base_address(bsp_vector_table_begin);
-
-    ctrl = arm_cp15_get_control();
-    ctrl &= ~ARM_CP15_CTRL_V;
-    arm_cp15_set_control(ctrl);
-  }
-}
-
-BSP_START_TEXT_SECTION static inline void arm_a8core_start_hook_1(void)
-{
-  arm_a8core_start_set_vector_base();
-}
-
-#ifdef __cplusplus
-}
-#endif /* __cplusplus */
-
-#endif /* LIBBSP_ARM_SHARED_ARM_A8CORE_START_H */
diff --git a/bsps/arm/include/bsp/arm-a9mpcore-start.h b/bsps/arm/include/bsp/arm-a9mpcore-start.h
index 5f870acec7..2a64ffc1d6 100644
--- a/bsps/arm/include/bsp/arm-a9mpcore-start.h
+++ b/bsps/arm/include/bsp/arm-a9mpcore-start.h
@@ -37,27 +37,6 @@
 extern "C" {
 #endif /* __cplusplus */
 
-BSP_START_TEXT_SECTION static inline void
-arm_a9mpcore_start_set_vector_base(void)
-{
-  /*
-   * Do not use bsp_vector_table_begin == 0, since this will get optimized away.
-  */
-  if (bsp_vector_table_end != bsp_vector_table_size) {
-    uint32_t ctrl;
-
-    /*
-     * For now we assume that every Cortex-A9 MPCore has the Security Extensions.
-     * Later it might be necessary to evaluate the ID_PFR1 register.
-     */
-    arm_cp15_set_vector_base_address(bsp_vector_table_begin);
-
-    ctrl = arm_cp15_get_control();
-    ctrl &= ~ARM_CP15_CTRL_V;
-    arm_cp15_set_control(ctrl);
-  }
-}
-
 BSP_START_TEXT_SECTION static inline void arm_a9mpcore_start_scu_invalidate(
   volatile a9mpcore_scu *scu,
   uint32_t cpu_id,
@@ -88,10 +67,11 @@ arm_a9mpcore_start_on_secondary_processor(void)
 {
   uint32_t ctrl;
 
-  arm_a9mpcore_start_set_vector_base();
-
   arm_gic_irq_initialize_secondary_cpu();
 
+  /* Change the VBAR from the start to the normal vector table */
+  arm_cp15_set_vector_base_address(bsp_vector_table_begin);
+
   ctrl = arm_cp15_start_setup_mmu_and_cache(
     0,
     ARM_CP15_CTRL_AFE | ARM_CP15_CTRL_Z
@@ -194,7 +174,6 @@ BSP_START_TEXT_SECTION static inline void arm_a9mpcore_start_global_timer(void)
 BSP_START_TEXT_SECTION static inline void arm_a9mpcore_start_hook_1(void)
 {
   arm_a9mpcore_start_global_timer();
-  arm_a9mpcore_start_set_vector_base();
 }
 
 #ifdef __cplusplus
diff --git a/bsps/arm/raspberrypi/start/bspsmp_init.c b/bsps/arm/raspberrypi/start/bspsmp_init.c
index a8c79e9f7c..a4dd470287 100644
--- a/bsps/arm/raspberrypi/start/bspsmp_init.c
+++ b/bsps/arm/raspberrypi/start/bspsmp_init.c
@@ -55,6 +55,9 @@ void rpi_start_rtems_on_secondary_processor(void)
 {
   uint32_t ctrl;
 
+  /* Change the VBAR from the start to the normal vector table */
+  arm_cp15_set_vector_base_address(bsp_vector_table_begin);
+
   ctrl = arm_cp15_start_setup_mmu_and_cache(
     0,
     ARM_CP15_CTRL_AFE | ARM_CP15_CTRL_Z
diff --git a/bsps/arm/raspberrypi/start/bspstarthooks.c b/bsps/arm/raspberrypi/start/bspstarthooks.c
index eb6546db1c..c46c4f5cbf 100644
--- a/bsps/arm/raspberrypi/start/bspstarthooks.c
+++ b/bsps/arm/raspberrypi/start/bspstarthooks.c
@@ -117,9 +117,6 @@ void BSP_START_TEXT_SECTION bsp_start_hook_0(void)
   /* Clear Translation Table Base Control Register */
   arm_cp15_set_translation_table_base_control_register(0);
 
-  /* Clear Secure or Non-secure Vector Base Address Register */
-  arm_cp15_set_vector_base_address(bsp_vector_table_begin);
-
 #ifdef RTEMS_SMP
   if (cpu_index_self == 0) {
     rpi_ipi_initialize();
diff --git a/bsps/arm/shared/start/start.S b/bsps/arm/shared/start/start.S
index 93590c1c36..9ebc2818e5 100644
--- a/bsps/arm/shared/start/start.S
+++ b/bsps/arm/shared/start/start.S
@@ -377,6 +377,20 @@ _start:
 
 #endif /* ARM_MULTILIB_VFP */
 
+#if (__ARM_ARCH >= 7 && __ARM_ARCH_PROFILE == 'A') || __ARM_ARCH >= 8
+	/*
+	 * Set VBAR to the vector table in the start section and make sure
+	 * SCTLR[V] is cleared.  Afterwards, exceptions are handled by RTEMS.
+	 */
+	ldr	r0, =bsp_start_vector_table_begin
+	dsb
+	mcr	p15, 0, r0, c12, c0, 0
+	mrc	p15, 0, r0, c1, c0, 0
+	bic	r1, r0, #0x2000
+	mcr	p15, 0, r1, c1, c0, 0
+	isb
+#endif
+
 	/*
 	 * Invoke the start hook 0.
 	 *
@@ -414,7 +428,7 @@ bsp_start_hook_0_done:
 	stmdb	sp!, {r4, r5, r6}
 
 	ldr	r0, =bsp_vector_table_begin
-	adr	r1, bsp_start_vector_table_begin
+	ldr	r1, =bsp_start_vector_table_begin
 	cmp	r0, r1
 	beq	.Lvector_table_copy_done
 	ldmia	r1!, {r2-r9}
@@ -424,6 +438,18 @@ bsp_start_hook_0_done:
 
 .Lvector_table_copy_done:
 
+#if (__ARM_ARCH >= 7 && __ARM_ARCH_PROFILE == 'A') || __ARM_ARCH >= 8
+	/*
+	 * This code path is only executed by the primary processor.  Set the
+	 * VBAR to the normal vector table.  For secondary processors, this is
+	 * done by bsp_start_hook_0().
+	 */
+	ldr	r0, =bsp_vector_table_begin
+	dsb
+	mcr	p15, 0, r0, c12, c0, 0
+	isb
+#endif
+
 	ldmia	sp!, {r0, r1, r2}
 
 	SWITCH_FROM_ARM_TO_THUMB	r3
diff --git a/bsps/arm/xen/start/bspstarthooks.c b/bsps/arm/xen/start/bspstarthooks.c
index 120535c60f..a9e1fbbfb1 100644
--- a/bsps/arm/xen/start/bspstarthooks.c
+++ b/bsps/arm/xen/start/bspstarthooks.c
@@ -28,7 +28,6 @@
 
 #include <bsp.h>
 #include <bsp/start.h>
-#include <bsp/arm-a9mpcore-start.h>
 
 BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 {
@@ -37,7 +36,6 @@ BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 
 BSP_START_TEXT_SECTION void bsp_start_hook_1(void)
 {
-  arm_a9mpcore_start_set_vector_base();
   bsp_start_copy_sections();
   bsp_xen_setup_mmu_and_cache();
   bsp_start_clear_bss();
diff --git a/bsps/arm/xilinx-zynqmp/start/bspstarthooks.c b/bsps/arm/xilinx-zynqmp/start/bspstarthooks.c
index 3a40a70d81..9ab8d965f3 100644
--- a/bsps/arm/xilinx-zynqmp/start/bspstarthooks.c
+++ b/bsps/arm/xilinx-zynqmp/start/bspstarthooks.c
@@ -35,7 +35,6 @@
 #include <bsp.h>
 #include <bsp/start.h>
 #include <bsp/arm-cp15-start.h>
-#include <bsp/arm-a9mpcore-start.h>
 
 BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 {
@@ -80,7 +79,6 @@ BSP_START_TEXT_SECTION void bsp_start_hook_0(void)
 
 BSP_START_TEXT_SECTION void bsp_start_hook_1(void)
 {
-  arm_a9mpcore_start_set_vector_base();
   bsp_start_copy_sections();
   zynqmp_setup_mmu_and_cache();
   bsp_start_clear_bss();
diff --git a/spec/build/bsps/arm/grp.yml b/spec/build/bsps/arm/grp.yml
index 8d2aba12ca..408288044f 100644
--- a/spec/build/bsps/arm/grp.yml
+++ b/spec/build/bsps/arm/grp.yml
@@ -15,7 +15,6 @@ install:
   - bsps/arm/include/uart.h
 - destination: ${BSP_INCLUDEDIR}/bsp
   source:
-  - bsps/arm/include/bsp/arm-a8core-start.h
   - bsps/arm/include/bsp/arm-a9mpcore-clock.h
   - bsps/arm/include/bsp/arm-a9mpcore-irq.h
   - bsps/arm/include/bsp/arm-a9mpcore-regs.h
-- 
2.26.2



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