The errno "variable" is required to be thread-specific.
It gets defined to a macro which dereferences a pointer
returned by a kernel function.
In user mode, we cannot simply read/write the thread struct.
We do not have thread-local storage mechanism, so for now
use the lowest address of the thread stack to store this
value, since this is guaranteed to be read/writable by
a user thread.
The downside of this approach is potential stack corruption
if the stack pointer goes down this far but does not exceed
the location, since a fault won't be generated in this case.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Newlib names this function __errno(), so if we want Zephyr to work
with Newlib seamlessly, it's better to just follow Newlib's naming
convention for Zephyr's own minimal libc.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.
Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.
Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file. Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.
Jira: ZEP-1457
Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Also remove mentions of unified kernel in various places in the kernel,
samples and documentation.
Change-Id: Ice43bc73badbe7e14bae40fd6f2a302f6528a77d
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
