On 10.11.2010, at 09:30, fengwei zhang <[email protected]> wrote: > Hi all, > > I am trying to impelement SMM support for K8/vt8237r, but I am strarking on > build smm handler bin. I understand I need to copy real smm handler to > location 0xa0000. From the ICH4 example, there are two extern varaibles > binary_smm_start and binary_smm_end, I know it defines in > /build/cpu/x86/smm/smm_wrap.ramstage.o. but how does that work?
The SMM handler is built as a separate binary and those external variables are set by the linker so the relocation code can find it. > Suppose I just want to put RSM instruction in the smmhandler, can I just > write instruction "0f aa"(bianry code of RSM) to location 0xa0000 and > 0xa0001. I tried this, but my machine went freeze after I invoke SMI. Besides what Patrick said about putting the code at 0xa8000 your relocation might went wrong. On power-on the SMM entry point is 0x38000 until it it moved to 0xa8000 > > I am thinking I may need to more instructons, because the SMM start with 16 > bits real mode, it may not recongnize the instruction, right? > But I am starking on how to build and copy SMM handler. I strongly suggest that you use and enhance the existing SMM handler. You will have to adapt two things - the code that opens the ASEG for writing from non-SMM (i82801gx_smi.c) - the north-/southbridge and CPU specific handlers (i82801gx_smihandler.c for example) > I would really appreciate if some one could help me this out. > > Best, > Fengwei Stefan -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
