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Setup MPU for code relocated to SRAM #34086

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Merged
merged 5 commits into from
May 4, 2021
Merged

Setup MPU for code relocated to SRAM #34086

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0bf5b52
Kconfig: Add a new config CODE_DATA_RELOCATION_SRAM
mmahadevan108 Apr 28, 2021
c052951
drivers: flash: MCUX: Split the relocate define based on target memory
mmahadevan108 Apr 28, 2021
7faafe9
scripts: Set align size for code relocated
mmahadevan108 Apr 6, 2021
370058b
arch: arm: Create a MPU entry for relocated code
mmahadevan108 Apr 5, 2021
0647fb0
arch: arm: Setup Static MPU regions earlier in boot flow
mmahadevan108 Apr 29, 2021
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9 changes: 0 additions & 9 deletions Kconfig.zephyr
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Expand Up @@ -62,15 +62,6 @@ config LINKER_ORPHAN_SECTION_ERROR

endchoice

config CODE_DATA_RELOCATION
bool "Relocate code/data sections"
depends on ARM
help
When selected this will relocate .text, data and .bss sections from
the specified files and places it in the required memory region. The
files should be specified in the CMakeList.txt file with
a cmake API zephyr_code_relocate().

config HAS_FLASH_LOAD_OFFSET
bool
help
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20 changes: 20 additions & 0 deletions arch/arm/Kconfig
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Expand Up @@ -34,6 +34,26 @@ config ARM_CUSTOM_INTERRUPT_CONTROLLER
family cores. The Cortex-M family cores are always equipped with
the ARM Nested Vectored Interrupt Controller (NVIC).

config CODE_DATA_RELOCATION
bool "Relocate code/data sections"
depends on CPU_CORTEX_M
help
When selected this will relocate .text, data and .bss sections from
the specified files and places it in the required memory region. The
files should be specified in the CMakeList.txt file with
a cmake API zephyr_code_relocate().

config CODE_DATA_RELOCATION_SRAM
bool "Relocate code/data sections to SRAM"
depends on CPU_CORTEX_M
select CODE_DATA_RELOCATION
help
When selected this will relocate .text, data and .bss sections from
the specified files and places it in SRAM. The files should be specified
in the CMakeList.txt file with a cmake API zephyr_code_relocate(). This
config is used to create an MPU entry for the SRAM space used for code
relocation.

rsource "core/aarch32/Kconfig"

endmenu
13 changes: 13 additions & 0 deletions arch/arm/core/aarch32/cortex_m/mpu/arm_core_mpu.c
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Expand Up @@ -55,6 +55,11 @@ extern K_THREAD_STACK_DEFINE(z_main_stack, CONFIG_MAIN_STACK_SIZE);
uint32_t z_arm_mpu_stack_guard_and_fpu_adjust(struct k_thread *thread);
#endif

#if defined(CONFIG_CODE_DATA_RELOCATION_SRAM)
extern char __sram_text_start[];
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@ioannisg ioannisg Apr 7, 2021

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Are these symbols defined anywhere?

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@mmahadevan108 mmahadevan108 Apr 7, 2021

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They get generated at build time and are placed in build/zephyr/include/generated/linker_relocate.ld

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@MaureenHelm MaureenHelm Apr 19, 2021

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This assumes we always relocate to the SRAM region, which isn't necessarily true. It's possible to relocate to other regions.

extern char __sram_text_size[];
#endif

static const struct z_arm_mpu_partition static_regions[] = {
#if defined(CONFIG_COVERAGE_GCOV) && defined(CONFIG_USERSPACE)
{
Expand Down Expand Up @@ -82,6 +87,14 @@ static const struct z_arm_mpu_partition static_regions[] = {
.attr = K_MEM_PARTITION_P_RX_U_RX,
},
#endif /* CONFIG_ARCH_HAS_RAMFUNC_SUPPORT */
#if defined(CONFIG_CODE_DATA_RELOCATION_SRAM)
{
/* RAM area for relocated text */
.start = (uint32_t)&__sram_text_start,
.size = (uint32_t)&__sram_text_size,
.attr = K_MEM_PARTITION_P_RX_U_RX,
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@ioannisg ioannisg May 4, 2021

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This partition has exactly the same attribution as the ramfunc section. I wonder if that one could be re-used. Not against, for now, to accept adding one more region. But i really do not see why we need to have 2 static regions with the same attribution.

},
#endif /* CONFIG_CODE_DATA_RELOCATION_SRAM */
#if !defined(CONFIG_MULTITHREADING) && defined(CONFIG_MPU_STACK_GUARD)
/* Main stack MPU guard to detect overflow.
* Note:
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6 changes: 2 additions & 4 deletions arch/arm/core/aarch32/cortex_m/mpu/arm_mpu.c
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Expand Up @@ -302,7 +302,7 @@ void arm_core_mpu_configure_dynamic_mpu_regions(const struct z_arm_mpu_partition
* This function provides the default configuration mechanism for the Memory
* Protection Unit (MPU).
*/
static int arm_mpu_init(const struct device *arg)
int z_arm_mpu_init(void)
{
uint32_t r_index;

Expand Down Expand Up @@ -416,8 +416,6 @@ static int arm_mpu_init(const struct device *arg)
NUM_MPU_REGIONS,
"Invalid number of MPU regions\n");
#endif /* CORTEX_M0PLUS || CPU_CORTEX_M3 || CPU_CORTEX_M4 */

return 0;
}

SYS_INIT(arm_mpu_init, PRE_KERNEL_1,
CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
14 changes: 1 addition & 13 deletions arch/arm/core/aarch32/cortex_m/mpu/nxp_mpu.c
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Expand Up @@ -601,10 +601,8 @@ void arm_core_mpu_configure_dynamic_mpu_regions(
* This function provides the default configuration mechanism for the Memory
* Protection Unit (MPU).
*/
static int nxp_mpu_init(const struct device *arg)
int z_arm_mpu_init(void)
{
ARG_UNUSED(arg);

uint32_t r_index;

if (mpu_config.num_regions > get_num_regions()) {
Expand Down Expand Up @@ -640,15 +638,5 @@ static int nxp_mpu_init(const struct device *arg)

arm_core_mpu_enable();


return 0;
}

#if defined(CONFIG_LOG)
/* To have logging the driver needs to be initialized later */
SYS_INIT(nxp_mpu_init, PRE_KERNEL_2,
CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
#else
SYS_INIT(nxp_mpu_init, PRE_KERNEL_1,
CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
#endif
10 changes: 0 additions & 10 deletions arch/arm/core/aarch32/thread.c
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Expand Up @@ -484,16 +484,6 @@ static void z_arm_prepare_switch_to_main(void)
__ISB();
#endif /* CONFIG_FPU_SHARING */
#endif /* CONFIG_FPU */

#ifdef CONFIG_ARM_MPU
/* Configure static memory map. This will program MPU regions,
* to set up access permissions for fixed memory sections, such
* as Application Memory or No-Cacheable SRAM area.
*
* This function is invoked once, upon system initialization.
*/
z_arm_configure_static_mpu_regions();
#endif
}

void arch_switch_to_main_thread(struct k_thread *main_thread, char *stack_ptr,
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11 changes: 11 additions & 0 deletions arch/arm/include/aarch32/kernel_arch_func.h
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Expand Up @@ -33,6 +33,7 @@ extern void z_arm_cpu_idle_init(void);
#ifdef CONFIG_ARM_MPU
extern void z_arm_configure_static_mpu_regions(void);
extern void z_arm_configure_dynamic_mpu_regions(struct k_thread *thread);
extern int z_arm_mpu_init(void);
#endif /* CONFIG_ARM_MPU */

static ALWAYS_INLINE void arch_kernel_init(void)
Expand All @@ -42,6 +43,16 @@ static ALWAYS_INLINE void arch_kernel_init(void)
z_arm_fault_init();
z_arm_cpu_idle_init();
z_arm_clear_faults();
#if defined(CONFIG_ARM_MPU)
z_arm_mpu_init();
/* Configure static memory map. This will program MPU regions,
* to set up access permissions for fixed memory sections, such
* as Application Memory or No-Cacheable SRAM area.
*
* This function is invoked once, upon system initialization.
*/
z_arm_configure_static_mpu_regions();
#endif
}

static ALWAYS_INLINE void
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3 changes: 2 additions & 1 deletion drivers/flash/Kconfig.mcux
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Expand Up @@ -48,7 +48,6 @@ config FLASH_MCUX_FLEXSPI_XIP
depends on MEMC_MCUX_FLEXSPI
depends on (CODE_FLEXSPI || CODE_FLEXSPI2)
select XIP
select CODE_DATA_RELOCATION
help
Allows using the flash API while running in XIP.
WARNING: It is possible to overwrite the running application itself.
Expand All @@ -64,9 +63,11 @@ choice FLASH_MCUX_FLEXSPI_XIP_MEM_TARGET

config FLASH_MCUX_FLEXSPI_XIP_MEM_ITCM
bool "ITCM"
select CODE_DATA_RELOCATION

config FLASH_MCUX_FLEXSPI_XIP_MEM_SRAM
bool "SRAM"
select CODE_DATA_RELOCATION_SRAM

endchoice

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10 changes: 7 additions & 3 deletions scripts/gen_relocate_app.py
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Expand Up @@ -257,9 +257,13 @@ def string_create_helper(region, memory_type,
linker_string += LINKER_SECTION_SEQ_MPU.format(memory_type.lower(), region, memory_type.upper(),
region.upper(), tmp, load_address_string, align_size)
else:
linker_string += LINKER_SECTION_SEQ.format(memory_type.lower(), region, memory_type.upper(),
region.upper(), tmp, load_address_string)

if memory_type == 'SRAM' and region == 'text':
align_size = 0
linker_string += LINKER_SECTION_SEQ_MPU.format(memory_type.lower(), region, memory_type.upper(),
region.upper(), tmp, load_address_string, align_size)
else:
linker_string += LINKER_SECTION_SEQ.format(memory_type.lower(), region, memory_type.upper(),
region.upper(), tmp, load_address_string)
if load_address_in_flash:
linker_string += SECTION_LOAD_MEMORY_SEQ.format(memory_type.lower(), region, memory_type.upper(),
region.upper())
Expand Down