Follow-up from here:
https://lists.rtems.org/pipermail/devel/2015-February/009974.html
This patch adds the macro BSP_NEEDS_REGISTER_INITIALIZATION and three hooks for
BSP-specific register init code to arm/shared/start.S. Said hooks are
bsp_init_registers_core (intended for initializing the ARM core registers),
bsp_init_registers_banked (for the FIQ mode banked registers) and
bsp_init_registers_vfp (for the FPU registers).
BSP_NEEDS_REGISTER_INITIALIZATION would be defined in a BSP's configure.ac (so
that it appears in its bspopts.h).
This patch also adds the register init code required by the TMS570. We've
tested it with the tms570ls3137_hdk.cfg config and it works fine.
--
c/src/lib/libbsp/arm/shared/start/start.S | 28
+++++++++++++++++++++++++
c/src/lib/libbsp/arm/tms570/Makefile.am | 1 +
c/src/lib/libbsp/arm/tms570/configure.ac | 5 +++++
c/src/lib/libbsp/arm/tms570/startup/bsp-init-registers.S | 89
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 123 insertions(+)
diff --git a/c/src/lib/libbsp/arm/shared/start/start.S
b/c/src/lib/libbsp/arm/shared/start/start.S
index f5f0fa4..fa884ee 100644
--- a/c/src/lib/libbsp/arm/shared/start/start.S
+++ b/c/src/lib/libbsp/arm/shared/start/start.S
@@ -48,6 +48,12 @@
.extern _ARMV4_Exception_fiq_default
.extern _ARMV7M_Exception_default
+#ifdef BSP_NEEDS_REGISTER_INITIALIZATION
+ .extern bsp_init_registers_core
+ .extern bsp_init_registers_banked
+ .extern bsp_init_registers_vfp
+#endif
+
/* Global symbols */
.globl _start
.globl bsp_start_vector_table_begin
@@ -127,6 +133,10 @@ _start:
* loader.
*/
+#ifdef BSP_NEEDS_REGISTER_INITIALIZATION
+ bl bsp_init_registers_core
+#endif
+
#ifdef RTEMS_SMP
/* Read MPIDR */
mrc p15, 0, r0, c0, c0, 5
@@ -161,6 +171,10 @@ _start:
add sp, r1
#endif
+#ifdef BSP_NEEDS_REGISTER_INITIALIZATION
+ bl bsp_init_registers_banked
+#endif
+
/* Enter ABT mode and set up the ABT stack pointer */
mov r0, #(ARM_PSR_M_ABT | ARM_PSR_I | ARM_PSR_F)
msr cpsr, r0
@@ -207,6 +221,11 @@ _start:
/* Enable FPU */
mov r0, #(1 << 30)
vmsr FPEXC, r0
+
+#ifdef BSP_NEEDS_REGISTER_INITIALIZATION
+ bl bsp_init_registers_vfp
+#endif
+
#endif /* ARM_MULTILIB_VFP */
/*
@@ -304,6 +323,10 @@ bsp_start_vector_table_end:
_start:
+#ifdef BSP_NEEDS_REGISTER_INITIALIZATION
+ bl bsp_init_registers_core
+#endif
+
#ifdef ARM_MULTILIB_VFP
/*
* Enable CP10 and CP11 coprocessors for privileged and user mode in
@@ -315,8 +338,13 @@ _start:
str r1, [r0]
dsb
isb
+
+#ifdef BSP_NEEDS_REGISTER_INITIALIZATION
+ bl bsp_init_registers_vfp
#endif
+#endif /* ARM_MULTILIB_VFP */
+
ldr sp, =bsp_stack_main_end
ldr lr, =bsp_start_hook_0_done + 1
b bsp_start_hook_0
diff --git a/c/src/lib/libbsp/arm/tms570/Makefile.am
b/c/src/lib/libbsp/arm/tms570/Makefile.am
index bf3465d..c10a145 100644
--- a/c/src/lib/libbsp/arm/tms570/Makefile.am
+++ b/c/src/lib/libbsp/arm/tms570/Makefile.am
@@ -85,6 +85,7 @@ libbsp_a_SOURCES += ../shared/startup/bsp-start-memcpy.S
libbsp_a_SOURCES += ../../shared/bsppretaskinghook.c
libbsp_a_SOURCES += startup/bspreset.c
libbsp_a_SOURCES += startup/bspstart.c
+libbsp_a_SOURCES += startup/bsp-init-registers.S
# POM
libbsp_a_SOURCES += pom/tms570-pom.c
diff --git a/c/src/lib/libbsp/arm/tms570/configure.ac
b/c/src/lib/libbsp/arm/tms570/configure.ac
index cefe50a..6b52e74 100644
--- a/c/src/lib/libbsp/arm/tms570/configure.ac
+++ b/c/src/lib/libbsp/arm/tms570/configure.ac
@@ -36,6 +36,11 @@ RTEMS_BSPOPTS_SET([BSP_MINIMUM_TASK_STACK_SIZE],[*],[1024])
RTEMS_BSPOPTS_HELP([BSP_MINIMUM_TASK_STACK_SIZE],[Suggested minimum task stack
size in bytes])
+RTEMS_BSPOPTS_SET([BSP_NEEDS_REGISTER_INITIALIZATION],[*],[1])
+RTEMS_BSPOPTS_HELP([BSP_NEEDS_REGISTER_INITIALIZATION],
+ [The TMS570 needs to have the registers of its CPU
initialized
+ to avoid CCMR4F errors])
+
RTEMS_BSPOPTS_SET([TMS570_OSCILLATOR_MAIN],[*],[12000000U])
RTEMS_BSPOPTS_HELP([TMS570_OSCILLATOR_MAIN],[main oscillator frequency in Hz])
diff --git a/c/src/lib/libbsp/arm/tms570/startup/bsp-init-registers.S
b/c/src/lib/libbsp/arm/tms570/startup/bsp-init-registers.S
new file mode 100644
index 0000000..1c58918
--- /dev/null
+++ b/c/src/lib/libbsp/arm/tms570/startup/bsp-init-registers.S
@@ -0,0 +1,89 @@
+/**
+ * @file bsp-init-registers.S
+ *
+ * @brief CPU register initialization routines for the TMS570.
+ */
+
+/*
+ * Copyright (c) 2015 Taller Technologies. All rights reserved.
+ *
+ * @author Martin Galvan <martin.gal...@tallertechnologies.com>
+ *
+ * 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.
+ */
+
+/*
+ * These routines perform the initialization of the CPU registers of the
TMS570.
+ * This is necessary because of the 1oo1D lockstep execution of the TMS570's
CCMR4F.
+ */
+
+#include <rtems/asm.h>
+
+.section .text
+.syntax unified
+.cpu cortex-r4
+.arm
+
+/* Initialization of the ARM core registers. */
+FUNCTION_ENTRY(bsp_init_registers_core)
+ mov r0, #0
+ mov r1, #0
+ mov r2, #0
+ mov r3, #0
+ mov r4, #0
+ mov r5, #0
+ mov r6, #0
+ mov r7, #0
+ mov r8, #0
+ mov r9, #0
+ mov r10, #0
+ mov r11, #0
+ mov r12, #0
+ mov r13, #0
+
+ bx lr
+FUNCTION_END(bsp_init_registers_core)
+
+/* Initialization of the FIQ mode banked registers. */
+FUNCTION_ENTRY(bsp_init_registers_banked)
+ mov r8, #0
+ mov r9, #0
+ mov r10, #0
+ mov r11, #0
+ mov r12, #0
+
+ bx lr
+FUNCTION_END(bsp_init_registers_banked)
+
+#ifdef ARM_MULTILIB_VFP
+
+/* Initialization of the FPU registers. */
+FUNCTION_ENTRY(bsp_init_registers_vfp)
+ stmfd sp!, {r0}
+
+ mov r0, #0
+ vmov d0, r0, r0
+ vmov d1, r0, r0
+ vmov d2, r0, r0
+ vmov d3, r0, r0
+ vmov d4, r0, r0
+ vmov d5, r0, r0
+ vmov d6, r0, r0
+ vmov d7, r0, r0
+ vmov d8, r0, r0
+ vmov d9, r0, r0
+ vmov d10, r0, r0
+ vmov d11, r0, r0
+ vmov d12, r0, r0
+ vmov d13, r0, r0
+ vmov d14, r0, r0
+ vmov d15, r0, r0
+
+ ldmfd sp!, {r0}
+
+ bx lr
+FUNCTION_END(bsp_init_registers_vfp)
+
+#endif /* ARM_MULTILIB_VFP */
