diff options
| author | Till Straumann <strauman@slac.stanford.edu> | 2008-07-10 21:28:38 +0000 |
|---|---|---|
| committer | Till Straumann <strauman@slac.stanford.edu> | 2008-07-10 21:28:38 +0000 |
| commit | 055173d46a688b402e20662c32e83eecb08c0a59 (patch) | |
| tree | 287c76b525948e08ceafcb79baef936960d860ff /c/src/lib/libcpu | |
| parent | 2008-07-10 Joel Sherrill <joel.sherrill@OARcorp.com> (diff) | |
| download | rtems-055173d46a688b402e20662c32e83eecb08c0a59.tar.bz2 | |
2008-07-10 Till Straumann <strauman@slac.stanford.edu>
* new-exceptions/bspsupport/README: added more information
Diffstat (limited to 'c/src/lib/libcpu')
| -rw-r--r-- | c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/README | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/README b/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/README index fc58482382..b6522312d4 100644 --- a/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/README +++ b/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/README @@ -388,3 +388,19 @@ RACE CONDITION WHEN DEALING WITH CRITICAL INTERRUPTS handler would not, eventually, check for a dispatch requirement). + And one more note: We never want to disable + machine-check exceptions to avoid a checkstop. + This means that we cannot use enabling/disabling + this type of exception for protection of critical + OS data structures. + Therefore, calling OS primitives from a asynchronous + machine-check handler is ILLEGAL and not supported. + Since machine-checks can happen anytime it is not + legal to test if a deferred context switch should + be performed when the asynchronous machine-check + handler returns (since _Context_Switch_is_necessary + could have been set by a IRQ-protected section of + code that was hit by the machine-check). + Note that synchronous machine-checks can legally + use OS primitives and currently there are no + asynchronous machine-checks defined. |