Commit Graph

3 Commits (c6ec8295e84ad8b64864b9595ca3a0cb5907d75e)

Author SHA1 Message Date
bebebib-rs b5f670f826
Fix pxTopOfStack calculation in configINIT_TLS_BLOCK for picolib (#739)
The pxTopOfStack calculation in configINIT_TLS_BLOCK for picolib needs
to decrement pxTopOfStack in order to meet the expectation of
 pxPortInitialiseStack function.
2 years ago
Keith Packard 563c57e7da
Fix TLS and stack alignment when using picolibc (#637)
Both the TLS block and stack must be correctly aligned when using
picolibc. The architecture stack alignment is represented by the
portBYTE_ALIGNMENT_MASK and the TLS block alignment is provided by the
Picolibc _tls_align() inline function for Picolibc version 1.8 and
above. For older versions of Picolibc, we'll assume that the TLS block
requires the same alignment as the stack.

For downward growing stacks, this requires aligning the start of the
TLS block to the maximum of the stack alignment and the TLS
alignment. With this, both the TLS block and stack will now be
correctly aligned.

For upward growing stacks, the two areas must be aligned
independently; the TLS block is aligned from the start of the stack,
then the tls space is allocated, and then the stack is aligned above
that.

It's probably useful to know here that the linker ensures that
variables within the TLS block are assigned offsets that match their
alignment requirements. If the TLS block itself is correctly aligned,
then everything within will also be.

I have only tested the downward growing stack branch of this patch.

Signed-off-by: Keith Packard <keithpac@amazon.com>
Co-authored-by: Keith Packard <keithpac@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago
Keith Packard c3e1df031e
Add Thread Local Storage (TLS) support using Picolibc functions (#343)
* Pass top of stack to configINIT_TLS_BLOCK

Picolibc wants to allocate the per-task TLS block within the stack
segment, so it will need to modify the top of stack value. Pass the
pxTopOfStack variable to make this explicit.

Signed-off-by: Keith Packard <keithpac@amazon.com>

* Move newlib-specific definitions to separate file

This reduces the clutter in FreeRTOS.h caused by having newlib-specific
macros present there.

Signed-off-by: Keith Packard <keithpac@amazon.com>

* Make TLS code depend only on configUSE_C_RUNTIME_TLS_SUPPORT

Remove reference to configUSE_NEWLIB_REENTRANT as that only works
when using newlib. configUSE_C_RUNTIME_TLS_SUPPORT is always
set when configUSE_NEWLIB_REENTRANT is set, so using both was
redundant in that case.

Signed-off-by: Keith Packard <keithpac@amazon.com>

* portable-ARC: Adapt ARC support to use generalized TLS support

With generalized thread local storage (TLS) support present in the
core, the two ARC ports need to have the changes to the TCB mirrored
to them.

Signed-off-by: Keith Packard <keithpac@amazon.com>

* Add Thread Local Storage (TLS) support using Picolibc functions

This patch provides definitions of the general TLS support macros in
terms of the Picolibc TLS support functions.

Picolibc is normally configured to use TLS internally for all
variables that are intended to be task-local, so these changes are
necessary for picolibc to work correctly with FreeRTOS.

The picolibc helper functions rely on elements within the linker
script to arrange the TLS data in memory and define some symbols.
Applications wanting to use this mechanism will need changes in their
linker script when migrating to picolibc.

Signed-off-by: Keith Packard <keithpac@amazon.com>

---------

Signed-off-by: Keith Packard <keithpac@amazon.com>
Co-authored-by: Keith Packard <keithpac@amazon.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
2 years ago