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2 Commits

Author SHA1 Message Date
Andrew Boie e56f61f5aa x86: exceptions: simplify exception stubs
Exception stubs now just push the handler and in some cases a dummy
error code before jumping to the exception handling code, never to
return.

Change-Id: I6a79d9243deb3fc7ccdae003dd0917364c0aa304
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2016-09-28 20:28:07 +00:00
Andrew Boie 17c0b372a2 x86: improve exception APIs
Previously, exception stubs had to be declared in assembly
language files. Now we have two new APIs to regsiter exception
handlers at C toplevel:

 _EXCEPTION_CONNECT_CODE(handler, vector)
 _EXCEPTION_CONNECT_NOCODE(handler, vector)

For x86 exceptions that do and do not push error codes onto
the stack respectively.

In addition, it's now no longer necessary to #define around
exception registration. We now use .gnu.linkonce magic such that
the first _EXCEPTION_CONNECT_*() that the linker finds is used
for the specified vector. Applications are free to install their
own exception handlers which will take precedence over default
handlers such as installed by arch/x86/core/fatal.c

Some Makefiles have been adjusted so that the default exception
handlers in arch/x86/core/fatal.c are linked last. The code has
been tested that the right order of precedence is taken for
exceptions overridden in the floating point, gdb debug, or
application code. The asm SYS_NANO_CPU_EXC_CONNECT API has been
removed; it was ill- conceived as it only worked for exceptions
that didn't push error codes. All the asm NANO_CPU_EXC_CONNECT_*
APIs are gone as well in favor of the new _EXCEPTION_CONNNECT_*()
APIs.

CONFIG_EXCEPTION_DEBUG no longer needs to be disabled for test
cases that define their own exception handlers.

Issue: ZEP-203
Change-Id: I782e0143fba832d18cdf4daaa7e47820595fe041
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2016-07-28 18:13:24 +00:00