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: Julian Achatzi <mail@achatzi.pro>
This reverts commit 88f6851a3d.
This is being reverted because it is redundant with the capabilities of
zephyr,memory-region and zephyr,memory-attr properties.
Signed-off-by: Declan Snyder <declan.snyder@nxp.com>
nocache ram is usually used by DMA to transfer data between
peripherals and ram. Some chips use isolated nocache ram,
which does not necessarily have to be in RAMABLE-REGION.
By specifying the zephyr,nocache-ram options, users can specify
the region where nocache-ram is located. If the user does not
specify it, it defaults to RAMABLE-REGION.
Signed-off-by: Weiwei Guo <guoweiwei@syriusrobotics.com>
This PR allows the user to add symbols to the nocache
section. The use for this could be as follows
zephyr_linker_sources_ifdef(CONFIG_NOCACHE_MEMORY
NOCACHE_SECTION
nocache.ld
)
nocache.ld (as shown below) can define additional
symbols to go into the nocache section
. = ALIGN(4);
KEEP(*(NonCacheable))
Signed-off-by: Mahesh Mahadevan <mahesh.mahadevan@nxp.com>
In some drivers, noncache memory need to be used for dma coherent
memroy, so add nocache memory segment mapping and support for ARM64
platforms.
The following variables definition example shows they will use nocache
memory allocation:
int var1 __nocache;
int var2 __attribute__((__section__(".nocache")));
Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>
No-cache SRAM section is currently used for ARM-only builds
with support for no-cacheable memory sections (i.e.
CONFIG_ARCH_HAS_NOCACHE_MEMORY_SUPPORT) and it holds
uninitialized data. This commit properly defines the
corresponding linker section using SECTION_DATA_PROLOGUE
and GROUP_DATA_LINK_IN macros.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
