Re: [LinuxBIOS] [LinuxBIOSv2] WIP Support for RCA RM4100 - i82830 Complete

Quoting Uwe Hermann :
> > /* First check if a DIMM is actually present. */
> > if (spd_read_byte(device, 2) == 0x4) {
> > 	print_debug("Found DIMM in slot ");
> > 	print_debug_hex8(i);
> > 	print_debug(", setting DRA...\r\n");
> > 	dra = 0x00;
> > 	/* columns */
> > 	col = spd_read_byte(device, 4);
> > 	/* data width */
> > 	width = spd_read_byte(device, 6);
> > 	/* calculate page size in bits */
> > 	value = ((1 << col) * width);
> > 	/* convert to Kilobytes */
> > 	dra = ((value / 8) >> 10);
> > 	/* # of banks of DIMM (single or double sided) */
> > 	value = spd_read_byte(device, 5);
> > 	if (value == 1) {
> > 		/* 2KB */
> > 		if (dra == 0x2) {
> > 			dra = 0xF0;
> > 		/* 4KB */
> > 		} else if (dra == 0x4) {
> > 			dra = 0xF1;
> > 		/* 8KB */
> > 		} else if (dra == 0x8) {
> > 			dra = 0xF2;
> > 		/* 16KB */
> > 		} else if (dra == 0x10) {
> > 			dra = 0xF3;
> > 		} else {
> > 			print_err("Page size not supported\r\n");
> > 			die("HALT\r\n");
> > 		}
> > 	} else if (value == 2) {
> > 		/* 2KB */
> > 		if (dra == 0x2) {
> > 			dra = 0x00;
> > 		/* 4KB */
> > 		} else if (dra == 0x4) {
> > 			dra = 0x11;
> > 		/* 8KB */
> > 		} else if (dra == 0x8) {
> > 			dra = 0x22;
> > 		/* 16KB */
> > 		} else if (dra == 0x10) {
> > 			dra = 0x33;
> > 		} else {
> > 			print_err("Page size not supported\r\n");
> > 			die("HALT\r\n");
> > 		}
>
> This code can be made a lot shorter using a table and a loop, I think.
>
> Uwe.

Uwe, I not really sure how I could use a table and a loop for this but  
would a switch be ok?

/* # of banks of DIMM (single or double sided) */
value = spd_read_byte(device, 5);

if (value == 1) {
    switch(dra) {
    	/* 2KB */
    	case 2:
    		dra = 0xF0;
    		break;
    	/* 4KB */
    	case 4:
    		dra = 0xF1;
    		break;
    	/* 8KB */
    	case 8:
    		dra = 0xF2;
    		break;
    	/* 16KB */
    	case 10:
    		dra = 0xF3;
    		break;
    	default:
    		print_err("Page size not supported\r\n");
    		die("HALT\r\n");
    }
} else if (value == 2) {
    switch(dra) {
    	/* 2KB */
    	case 2:
    		dra = 0x00;
    		break;
    	/* 4KB */
    	case 4:
    		dra = 0x11;
    		break;
    	/* 8KB */
    	case 8:
    		dra = 0x22;
    		break;
    	/* 16KB */
    	case 10:
    		dra = 0x33;
    		break;
    	default:
    		print_err("Page size not supported\r\n");
    		die("HALT\r\n");
    }
}else {
    print_err("# of banks of DIMM not supported\r\n");
    die("HALT\r\n");
}

Thanks - Joe