[rtems commit] score: Document _TLS_Alignment

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    96402b74a85cd8506f022796c547bf00f6bd4031
Changeset: http://git.rtems.org/rtems/commit/?id=96402b74a85cd8506f022796c547bf00f6bd4031

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Mon Mar 23 16:16:18 2020 +0100

score: Document _TLS_Alignment

---

 cpukit/include/rtems/score/tls.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/cpukit/include/rtems/score/tls.h b/cpukit/include/rtems/score/tls.h
index bfe6ff3..65a49d8 100644
--- a/cpukit/include/rtems/score/tls.h
+++ b/cpukit/include/rtems/score/tls.h
@@ -58,6 +58,16 @@ extern char _TLS_BSS_size[];
 
 extern char _TLS_Size[];
 
+/**
+ * @brief The TLS section alignment.
+ *
+ * This symbol is provided by the linker command file as the maximum alignment
+ * of the .tdata and .tbss sections.  The linker ensures that the first TLS
+ * output section is aligned to the maximum alignment of all TLS output
+ * sections, see function _bfd_elf_tls_setup() in bfd/elflink.c of the GNU
+ * Binutils sources.  The linker command file must take into account the case
+ * that the .tdata section is empty and the .tbss section is non-empty.
+ */
 extern char _TLS_Alignment[];
 
 typedef struct {