arm: armv6-m: Support relocating vector table

An abnormal crash was encountered in ARMv6-M SoCs that don't have flash
starting at 0.  With Zephyr OS the reason for this crash is that, on
ARMv6-M the system requires an exception vector table at the 0 address.

We implement the relocate_vector_table function to move the vector table
code to address 0 on systems which don't have the start of code already
at 0.

[kumar.gala: reworderd commit message, tweaked how we check if we need
 to copy vector table]

Signed-off-by: Xiaorui Hu <xiaorui.hu@linaro.org>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This commit is contained in:
Xiaorui Hu 2017-06-23 11:02:50 +08:00 committed by Anas Nashif
commit eb48a0a73c
3 changed files with 17 additions and 3 deletions

View file

@ -22,9 +22,20 @@
#include <linker/linker-defs.h>
#include <nano_internal.h>
#include <arch/arm/cortex_m/cmsis.h>
#include <string.h>
#ifdef CONFIG_ARMV6_M
static inline void relocate_vector_table(void) { /* do nothing */ }
#define VECTOR_ADDRESS 0
static inline void relocate_vector_table(void)
{
#if defined(CONFIG_XIP) && (CONFIG_FLASH_BASE_ADDRESS != 0) || \
!defined(CONFIG_XIP) && (CONFIG_SRAM_BASE_ADDRESS != 0)
size_t vector_size = (size_t)_vector_end - (size_t)_vector_start;
memcpy(VECTOR_ADDRESS, _vector_start, vector_size);
#endif
}
#elif defined(CONFIG_ARMV7_M)
#ifdef CONFIG_XIP
#define VECTOR_ADDRESS ((uintptr_t)&_image_rom_start + \

View file

@ -94,7 +94,7 @@ SECTIONS
KEEP(*(.dbghdr))
KEEP(*(".dbghdr.*"))
#endif
_vector_start = .;
. = CONFIG_TEXT_SECTION_OFFSET;
KEEP(*(.exc_vector_table))
KEEP(*(".exc_vector_table.*"))
@ -112,7 +112,7 @@ SECTIONS
#ifdef CONFIG_GEN_SW_ISR_TABLE
KEEP(*(SW_ISR_TABLE))
#endif
_vector_end = .;
_image_text_start = .;
*(.text)
*(".text.*")

View file

@ -208,6 +208,9 @@ extern char _image_text_end[];
extern char _image_rodata_start[];
extern char _image_rodata_end[];
extern char _vector_start[];
extern char _vector_end[];
/* end address of image, used by newlib for the heap */
extern char _end[];