Commit f9168ae4 authored by Julian Achatzi's avatar Julian Achatzi Committed by Benjamin Cabé
Browse files

arch: common: Make nocache region loadable 



The `nocache` is not loadable, thus data stored therein cannot be
initialized by the startup code. This might be needed in special
cases. E.g. One might have a buffer which one wants to DMA into,
and which is a member of a struct. Other members of the struct one
may want to have initialized by the startup code.
The buffer thus should be placed in the `nocache` region, but for
the other members of the buffer to be initialized by the startup
code, the `nocache` region needs to be loadable.

Fix it by making the `nocache` region loadable. Adding a KConfig
symbol to do this optionally was considered, but deemed unnecessary
during the PR.

Signed-off-by: default avatarJulian Achatzi <mail@achatzi.pro>
parent 25564f73

arch/common/nocache.ld

+3 −2
Original line number Diff line number Diff line
@@ -8,7 +8,7 @@ 
/* Copied from linker.ld */



/* Non-cached region of RAM */

SECTION_DATA_PROLOGUE(_NOCACHE_SECTION_NAME,(NOLOAD),)

SECTION_DATA_PROLOGUE(_NOCACHE_SECTION_NAME,,)

{

#if defined(CONFIG_MMU)

	MMU_ALIGN;
@@ -27,5 +27,6 @@ SECTION_DATA_PROLOGUE(_NOCACHE_SECTION_NAME,(NOLOAD),) 
	MPU_ALIGN(_nocache_ram_size);

#endif

	_nocache_ram_end = .;

} GROUP_DATA_LINK_IN(RAMABLE_REGION, RAMABLE_REGION)

} GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)

_nocache_ram_size = _nocache_ram_end - _nocache_ram_start;

_nocache_load_start = LOADADDR(_NOCACHE_SECTION_NAME);

include/zephyr/linker/linker-defs.h

+1 −0
Original line number Diff line number Diff line
@@ -225,6 +225,7 @@ extern char __sg_size[]; 
extern char _nocache_ram_start[];

extern char _nocache_ram_end[];

extern char _nocache_ram_size[];

extern char _nocache_load_start[];

#endif /* CONFIG_NOCACHE_MEMORY */



/* Memory owned by the kernel. Start and end will be aligned for memory

kernel/xip.c

+6 −0
Original line number Diff line number Diff line
@@ -31,6 +31,12 @@ void z_data_copy(void) 
	z_early_memcpy(&__ramfunc_region_start, &__ramfunc_load_start,

		       __ramfunc_end - __ramfunc_region_start);

#endif /* CONFIG_ARCH_HAS_RAMFUNC_SUPPORT */

#ifdef CONFIG_ARCH_HAS_NOCACHE_MEMORY_SUPPORT

#if CONFIG_NOCACHE_MEMORY

	z_early_memcpy(&_nocache_ram_start, &_nocache_load_start,

		       (uintptr_t) &_nocache_ram_size);

#endif /* CONFIG_NOCACHE_MEMORY */

#endif /* CONFIG_ARCH_HAS_NOCACHE_MEMORY_SUPPORT */

#if DT_NODE_HAS_STATUS_OKAY(DT_CHOSEN(zephyr_ccm))

	z_early_memcpy(&__ccm_data_start, &__ccm_data_load_start,

		       __ccm_data_end - __ccm_data_start);

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