sis630 IPL read wrong number of SPD RAM type

zhu shi song zhushisongzhu at
Thu Jul 15 08:51:01 CEST 2004

(1)  RAM type sis630 IPL.S read is not 04
I debug sis630 IPL.S,  I find the RAM type value that IPL read is 01 or 00 for different RAM but not 04.  But my RAM is definitely SDRAM.  The code is:
movb	$0x02, %al # Read the RAM Type (SPD byte 2)
	CALL_SP(read_spd) # of the dram on current DIMM.
movb %bl, %al     # %bl is 01 or 00 for different RAM,not 04
outb %al, $0x80
 cmpb	$0x04, %bl # If the RAM Type = SDRAM ??
	jne	no_sdram 	# no, exit
Is there any bug in the codes reading spd bytes?
(2) for some Sis630 mainboard, docipl will hang. Linuxbios can't be executed.  I think the RAM initialization procedure is as compatible as BIOS.

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