[PATCH v2 02/18] ARM: ARMv7M: Enlarge vector table to 256 entries

From: Maxime Coquelin
Date: Fri Feb 20 2015 - 13:08:13 EST


>From Cortex-M reference manuals, the nvic supports up to 240 interrupts.
So the number of entries in vectors table is up to 256.

This patch adds a new config flag to specify the number of external interrupts.
Some ifdeferies are added in order to respect the natural alignment without
wasting too much space on smaller systems.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
---
arch/arm/kernel/entry-v7m.S | 13 +++++++++----
arch/arm/mm/Kconfig | 15 +++++++++++++++
2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/entry-v7m.S b/arch/arm/kernel/entry-v7m.S
index 8944f49..68cde36 100644
--- a/arch/arm/kernel/entry-v7m.S
+++ b/arch/arm/kernel/entry-v7m.S
@@ -117,9 +117,14 @@ ENTRY(__switch_to)
ENDPROC(__switch_to)

.data
- .align 8
+#if CONFIG_CPUV7M_NUM_IRQ <= 112
+ .align 9
+#else
+ .align 10
+#endif
+
/*
- * Vector table (64 words => 256 bytes natural alignment)
+ * Vector table (Natural alignment need to be ensured)
*/
ENTRY(vector_table)
.long 0 @ 0 - Reset stack pointer
@@ -138,6 +143,6 @@ ENTRY(vector_table)
.long __invalid_entry @ 13 - Reserved
.long __pendsv_entry @ 14 - PendSV
.long __invalid_entry @ 15 - SysTick
- .rept 64 - 16
- .long __irq_entry @ 16..64 - External Interrupts
+ .rept CONFIG_CPUV7M_NUM_IRQ
+ .long __irq_entry @ External Interrupts
.endr
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index c43c714..27eb835 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -604,6 +604,21 @@ config CPU_USE_DOMAINS
This option enables or disables the use of domain switching
via the set_fs() function.

+config CPUV7M_NUM_IRQ
+ int "Number of external interrupts connected to the NVIC"
+ depends on CPU_V7M
+ default 90 if ARCH_STM32
+ default 38 if ARCH_EFM32
+ default 240
+ help
+ This option indicates the number of interrupts connected to the NVIC.
+ The value can be larger than the real number of interrupts supported
+ by the system, but must not be lower.
+ The default value is 240, corresponding to the maximum number of
+ interrupts supported by the NVIC on Cortex-M family.
+
+ If unsure, keep default value.
+
#
# CPU supports 36-bit I/O
#
--
1.9.1

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