Hi All, The MIPS ABI document says: For non-leaf function,$31 must be saved. If any of $16..$23 or$29..$31 is changed within the called function, it must be saved in the stack frame before use and restored from the stack frame before re- turn from the function. My interrupt/exception handler contains two parts: one written in assembly and the other written in C. The ASM handler does some simple work like saving status, epc and gerneral registers and then jumps/calls to the C handler to do more complex work. Since MIPS ABI guarantees $16~$23 and $29~$31 are saved in C functions if they are used, is it safe to save only those registers except $16~$23 and $29~$31 in ASM handler? Best regards PRC June 13, 2008
