Re: [LinuxBIOS] DIMM Page Size

[Joseph Smith]

Ok, here is my DRA function for i82830 raminit.c. Feedback,  
suggestions welcome. If there is any easier way to write this please  
let me know. I am still a newbie at C, but learning quickly. If the  
format looks funky, blaime Horde IMAP.

Thanks - Joe

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static void set_dram_row_attributes(const struct mem_controller *ctrl)
{
    int i, dra, col, width, page_size;

for (i = 0; i < DIMM_SOCKETS; i++) {
    	/* First check if a DIMM is actually present. */
    	if (smbus_read_byte(ctrl->channel0[i], 2) == 4) {
    		print_debug("Found DIMM in slot ");
    		print_debug_hex8(i);
    		print_debug(", Setting DRA...\r\n");

dra = 0x00;

/* columns */
    		col = smbus_read_byte(ctrl->channel0[i], 4);

/* data width */
    		width = smbus_read_byte(ctrl->channel0[i], 6);

/* calculate page size in bits */
    		page_size = ((1 << col) * width);

/* convert to Kilobytes */
    		dra = ((page_size / 8) >> 10);

/* 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_debug("Page Size not supported\r\n");
    			die("HALT!\r\n");
    		}
    	} else {
    		print_debug("No DIMM found in slot ");
    		print_debug_hex8(i);
    		print_debug(", Setting DRA to 0xFF\r\n");

/* If there's no DIMM in the slot, set dra value to 0xFF. */
    		dra = 0xFF;
    	}

/* Set the value for DRAM Row Attribute Registers */
       	         pci_write_config8(ctrl->d0, DRA + i, dra);
    	print_debug("DRA ");
    	print_debug_hex8(DRA + i);
    	print_debug(" has been set to ");
    	print_debug_hex8(dra);
    	print_debug("\r\n");
    }
}