Hi Chris, I think the best way to solve the issue should adjust the stack alignment automaticly by kernel. For most of ecos users do not care the stack alignment. If they create their own applications with the template of package/example/twothreads.c(or serial.c, simple-alarm.c), I don't how many hidden bugs in ecos world!
Xiaochen Zhou ----- Original Message ----- From: "Chris Zimman" <[EMAIL PROTECTED]> To: "Xiaochen Zhou" <[EMAIL PROTECTED]>; <[email protected]> Sent: Friday, May 23, 2008 6:32 PM Subject: RE: [ECOS] stack base pointer not align to 4 bytes > If I change the line static char g_IC_Stack[IC_STACK_SIZE]; ----------> > static int g_IC_Stack[IC_STACK_SIZE/4]; everything is OK. > > I think this is my fault, but when I grep the eCos source tree, thera > are many files using stack definition like me( for example: > net/tcpip/current/src/ecos/support.c). And the kernel source > code(Cyg_HardwareThread::attach_stack()) did not adjust the alignment > automaticly. > > My fault or eCos fault? Thanks! It's not really a 'fault' either way, but if you have it declared as char, it's definitely not guaranteed to be word aligned. I think the examples you point out in eCos are probably bugs, at least on platforms that need aligned access. An alternative means for specifying alignment is to use __attribute__((aligned)), eg. static char g_IC_Stack[IC_STACK_SIZE] __attribute__((aligned(4))); --Chris -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
