On 24 June 2016 at 03:21, Andrew Jeffery <[email protected]> wrote: > On Thu, 2016-06-23 at 18:39 +0100, Peter Maydell wrote: >> On 23 June 2016 at 03:15, Andrew Jeffery <[email protected]> wrote: >> > >> > The magic constant configures the following options: >> > >> > * 28:27: Configure DRAM size as 256MB >> > * 26:24: DDR3 SDRAM with CL = 6, CWL = 5 >> > * 23: Configure 24/48MHz CLKIN >> > * 22: Disable GPIOE pass-through mode >> > * 21: Disable GPIOD pass-through mode >> > * 20: Enable LPC decode of SuperIO 0x2E/0x4E addresses >> > * 19: Disable ACPI >> > * 18: Configure 48MHz CLKIN >> > * 17: Disable BMC 2nd boot watchdog timer >> > * 16: Decode SuperIO address 0x2E >> > * 15: VGA Class Code >> > * 14: Enable LPC dedicated reset pin >> > * 13:12: Enable SPI Master and SPI Slave to AHB Bridge >> > * 11:10: Select CPU:AHB ratio = 2:1 >> > * 9:8: Select 384MHz H-PLL >> > * 7: Configure MAC#2 for RMII/NCSI >> > * 6: Configure MAC#1 for RMII/NCSI >> > * 5: No VGA BIOS ROM >> > * 4: Boot using 32bit SPI address mode >> > * 3:2: Select 16MB VGA memory >> > * 1:0: Boot from SPI flash memory >> Maybe we should say this in a comment in the code? > > The list describes our specific value choices in the register's > bitfields rather than fully documenting the bitfields and values. If > you prefer I could switch to the latter and make it a comment, but > failing that my only thought was if we tweaked the value the comment > maybe come out of sync. By putting our choices in the commit message > the description is at least accurate for what was configured at the > time.
I'd just like some idea of where the magic number comes from. At the moment the source code doesn't even have a reference to a data sheet that would indicate where to look. thanks -- PMM
