I've just run across an interesting problem building a big-endian MIPS kernel against the kernel source from the cvs tree. When the drive identity record is presented to the ide_fix_driveid() function in include/asm-mips/ide.h, it looks like its been byteswapped in 16 bit chunks. Needless to say, this causes a certain amount of confusion. I tried following the process back to the point where the data is read in, but I failed to find anything that seemed to be explicitly swapping the code. The older kernel that I have 2.4.3 works Ok, so it's something that's happened recently. Here's a little bit of debug information that I collected.. I messed around with the ide_fix_driveid function till I got the system to work, but I'm be embarassed to see that code escape into the wild. This is a dump of the id record before the call to ide_fix_driveid() in the 2.4.3 kernel. 0000: 7a42ff3f 00001000 00e15802 3f001000 "zB.?......X.?..." 0010: 00000e00 4457572d 41435441 34343430 "....DWW.ACTA4440" 0020: 33340034 00000000 03000010 28003630 "34.4..........60" 0030: 302e4734 36304457 20434457 30334530 "0.G460DW.CDW03E0" 0040: 2d423030 50433046 20202020 20202020 ".B00PC0F........" 0050: 20202020 20202020 20202020 20201080 "................" 0060: 0000002f 01408002 00000700 ff3f1000 ".....@.......?.." 0070: 3f0010fc fb000001 80ac7e03 00000704 "?.........~....." 0080: 03007800 78007800 78000000 00000000 "..x.x.x.x......." 0090: 00000000 00000000 00000000 00000000 "................" 00a0: 3e000000 6b34014b 00406934 01080040 ">...k4.K.@i4...@" 00b0: 3f000000 00000000 00004b60 fe800000 "?.........K`...." 00c0: 00000000 00000000 00000000 00000000 "................" 00d0: 00000000 00000000 00000000 00000000 "................" 00e0: 00000000 00000000 00000000 00000000 "................" 00f0: 00000000 00000000 00000000 00000000 "................" 0100: 01000000 00000000 00003300 00000000 "..........3....." 0110: 00000000 00000000 00000000 00000000 "................" 0120: 00000000 00000000 00000000 00000000 "................" 0130: 00000000 00000000 00000000 00001f00 "................" 0140: 00000000 00000000 00000000 00000000 "................" 0150: 00000000 00000000 00000000 00000000 "................" 0160: 00000000 00000000 00000000 00000000 "................" 0170: 00000000 00000000 00000000 00000000 "................" 0180: 00000000 00000000 00000000 00000000 "................" 0190: 00000000 00000000 00000000 00000000 "................" 01a0: 00000000 00000000 00000000 00000000 "................" 01b0: 00000000 00000000 00000000 00000000 "................" 01c0: 00000000 00000000 00000000 00000000 "................" 01d0: 00000000 00000000 00000000 00000000 "................" 01e0: 00000000 00000000 00000000 00000000 "................" 01f0: 00000000 00000000 00000000 0000a56e "...............n" This is a dump of the id record before the call to ide_fix_drived() in the 2.4.18 kernel from cvs. 0000: 427a3fff 00000010 e1000258 003f0010 "Bz?........X.?.." 0010: 0000000e 57442d57 43414154 34343034 "....WD.WCAAT4404" 0020: 34333400 00000000 00031000 00283036 "434...........06" 0030: 2e303447 30365744 43205744 33303045 ".04G06WDC.WD300E" 0040: 422d3030 43504630 20202020 20202020 "B.00CPF0........" 0050: 20202020 20202020 20202020 20208010 "................" 0060: 00002f00 40010280 00000007 3fff0010 "....@.......?..." 0070: 003ffc10 00fb0100 ac80037e 00000407 ".?.........~...." 0080: 00030078 00780078 00780000 00000000 "...x.x.x.x......" 0090: 00000000 00000000 00000000 00000000 "................" 00a0: 003e0000 346b4b01 40003469 08014000 ".>..4kK.@.4i..@." 00b0: 003f0000 00000000 0000604b 80fe0000 ".?........`K...." 00c0: 00000000 00000000 00000000 00000000 "................" 00d0: 00000000 00000000 00000000 00000000 "................" 00e0: 00000000 00000000 00000000 00000000 "................" 00f0: 00000000 00000000 00000000 00000000 "................" 0100: 00010000 00000000 00000033 00000000 "...........3...." 0110: 00000000 00000000 00000000 00000000 "................" 0120: 00000000 00000000 00000000 00000000 "................" 0130: 00000000 00000000 00000000 0000001f "................" 0140: 00000000 00000000 00000000 00000000 "................" 0150: 00000000 00000000 00000000 00000000 "................" 0160: 00000000 00000000 00000000 00000000 "................" 0170: 00000000 00000000 00000000 00000000 "................" 0180: 00000000 00000000 00000000 00000000 "................" 0190: 00000000 00000000 00000000 00000000 "................" 01a0: 00000000 00000000 00000000 00000000 "................" 01b0: 00000000 00000000 00000000 00000000 "................" 01c0: 00000000 00000000 00000000 00000000 "................" 01d0: 00000000 00000000 00000000 00000000 "................" 01e0: 00000000 00000000 00000000 00000000 "................" 01f0: 00000000 00000000 00000000 00006ea5 "..............n." -- work -> kenaaker@silverbacksystems.com (507) 289-6910 ext 1 home -> kenaaker@screaminet.com
