Hi, I am trying to port eCos on MPC8555 processor . MPC8260 is the baseline I considered .
In MPC8555E processor when a reset occurs , control will go to location FFFF_FFFC. This particular location always contain a branch instruction to boot page. In MPC8260 ecos2.0b1 code control will go to the point "_exception_reset " and the startup file is "vectors.S" . ( As specified in the linker script file " powerpc.ld ") This " _exception_reset " comes under " .vectors " section Well now , my problem is , it is not possible to load " .vectors " section at address starting from FFFF_FFFC, because this section is bigger to hold at addresses FFF_FFFC, FFFF_FFFD,FFFF_FFFE and FFFF_FFFF. In Uboot code for MPC8555E , there is a separated file " resetvec.S " ,this contain a single branch instruction to _start( which is in the file start.S ) . This branch insrtuction is under the section " .resetvec " . This section can be loaded at FFFF_FFFC , because it contain only one instruction . One silution is to use the way what Uboot had done, but we have to change linker script file (powerpc.ld ). This is not possible ,because it is under " arch " directory . Is there any other solution to come out of this ? Thanks Dileep Kumar -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
