diff options
| author | Jerome Forissier <[email protected]> | 2025-04-18 16:09:34 +0200 |
|---|---|---|
| committer | Tom Rini <[email protected]> | 2025-04-23 13:19:44 -0600 |
| commit | f9384796179abcc7e5796815c79b2137f5f83b12 (patch) | |
| tree | 2254c00b727719c904ffdbd9cc9ca0fbcaa066fa /doc/api | |
| parent | b989f9ed9fe13be2cb168d2d45c235f011104f38 (diff) | |
uthread: add cooperative multi-tasking interface
Add a new internal API called uthread (Kconfig symbol: UTHREAD) which
provides cooperative multi-tasking. The goal is to be able to improve
the performance of some parts of U-Boot by overlapping lengthy
operations, and also implement background jobs in the U-Boot shell.
Each uthread has its own stack allocated on the heap. The default stack
size is defined by the UTHREAD_STACK_SIZE symbol and is used when
uthread_create() receives zero for the stack_sz argument.
The implementation is based on context-switching via initjmp()/setjmp()/
longjmp() and is inspired from barebox threads [1]. A notion of thread
group helps with dependencies, such as when a thread needs to block
until a number of other threads have returned.
The name "uthread" comes from "user-space threads" because the
scheduling happens with no help from a higher privileged mode, contrary
to more complex models where kernel threads are defined. But the 'u'
may as well stand for 'U-Boot' since the bootloader may actually be
running at any privilege level and the notion of user vs. kernel may
not make much sense in this context.
[1] https://github.com/barebox/barebox/blob/master/common/bthread.c
Signed-off-by: Jerome Forissier <[email protected]>
Reviewed-by: Ilias Apalodimas <[email protected]>
Diffstat (limited to 'doc/api')
| -rw-r--r-- | doc/api/index.rst | 1 | ||||
| -rw-r--r-- | doc/api/uthread.rst | 7 |
2 files changed, 8 insertions, 0 deletions
diff --git a/doc/api/index.rst b/doc/api/index.rst index 0dc9ad45d41..506843ed74a 100644 --- a/doc/api/index.rst +++ b/doc/api/index.rst @@ -29,3 +29,4 @@ U-Boot API documentation sysreset timer unicode + uthread diff --git a/doc/api/uthread.rst b/doc/api/uthread.rst new file mode 100644 index 00000000000..21233ff6b22 --- /dev/null +++ b/doc/api/uthread.rst @@ -0,0 +1,7 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Uthread API +=========== + +.. kernel-doc:: include/uthread.h + :internal: |