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arch: arm: mpu: Make XN bit conditional on CONFIG_XIP for RAM region

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Make the execute never (XN) bit conditonal on CONFIG_XIP for the RAM MPU
region attribute. This is required because when CONFIG_XIP is not set,
the entire image will be linked into SRAM. In this case, SRAM must be
executable.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>
This commit is contained in:
Daniel DeGrasse 2023-08-16 22:18:08 +00:00 • committed by Carles Cufí
commit 3926134f8e
2 changed files with 12 additions and 2 deletions
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7
include/zephyr/arch/arm/aarch32/mpu/arm_mpu_v7m.h
View file

@ -110,10 +110,15 @@
#define REGION_4G REGION_SIZE(4GB)
/* Some helper defines for common regions */
/* On Cortex-M, we can only set the XN bit when CONFIG_XIP=y. When
* CONFIG_XIP=n, the entire image will be linked to SRAM, so we need to keep
* the SRAM region XN bit clear or the application code will not be executable.
*/
#define REGION_RAM_ATTR(size) \
{ \
(NORMAL_OUTER_INNER_WRITE_BACK_WRITE_READ_ALLOCATE_NON_SHAREABLE | \
MPU_RASR_XN_Msk | size | P_RW_U_NA_Msk) \
IF_ENABLED(CONFIG_XIP, (MPU_RASR_XN_Msk |)) size | P_RW_U_NA_Msk) \
}
#define REGION_RAM_NOCACHE_ATTR(size) \
{ \

7
include/zephyr/arch/arm/aarch32/mpu/arm_mpu_v8.h
View file

@ -245,9 +245,14 @@
.r_limit = limit - 1, \
}
#else
/* On Cortex-M, we can only set the XN bit when CONFIG_XIP=y. When
* CONFIG_XIP=n, the entire image will be linked to SRAM, so we need to keep
* the SRAM region XN bit clear or the application code will not be executable.
*/
#define REGION_RAM_ATTR(base, size) \
{\
.rbar = NOT_EXEC | \
.rbar = IF_ENABLED(CONFIG_XIP, (NOT_EXEC |)) \
P_RW_U_NA_Msk | NON_SHAREABLE_Msk, /* AP, XN, SH */ \
/* Cache-ability */ \
.mair_idx = MPU_MAIR_INDEX_SRAM, \