Re: [coreboot] [PATCH] SB700: enable PrefetchEnSPIFromHost to improve boot time from SPI flash

[Stefan Reinauer]

On 10/17/10 6:49 PM, Scott Duplichan wrote:
> This patch enables SB700 option PrefetchEnSPIFromHost in early setup.
> It affects only systems booting from SPI flash, not those booting from
> LPC flash. By default, the SB700 reads dwords from the SPI flash chip.
> Setting PrefetchEnSPIFromHost causes the SB700 to read entire cache
> lines from the flash chip.
>
> Thanks,
> Scott
>
> Signed-off-by: Scott Duplichan

Acked-by: Stefan Reinauer
> Index: src/southbridge/amd/sb700/sb700_early_setup.c
>
> --- src/southbridge/amd/sb700/sb700_early_setup.c       (revision 5964)
> +++ src/southbridge/amd/sb700/sb700_early_setup.c       (working copy)
> @@ -129,6 +129,11 @@
>         reg8 |= (1 << 5) | (1 << 6);
>         pci_write_config8(dev, 0x47, reg8);
>   /* Enable PrefetchEnSPIFromHost to speed up SPI flash read (does not affect LPC) */
>   reg8 = pci_read_config8(dev, 0xbb);
>   reg8 |= 1 << 0;
>   pci_write_config8(dev, 0xbb, reg8);
>   /* SuperIO, LPC ROM */
>   reg8 = pci_read_config8(dev, 0x48);
>   /* Decode ports 0x2e-0x2f, 0x4e-0x4f (SuperI/O configuration) */