[U-Boot] u-boot: x86: interrupt mapping

Christian Gmeiner christian.gmeiner at gmail.com
Tue Jul 19 08:02:13 CEST 2016


Hi Bin

>>
>> For the moment I have no answer to this question. I need to dive into
>> the vxworks code, which
>> is not what I like to do now (but needs to be done)-
>>
>
> Yes, please do track it down. The interrupt line register configured
> by U-Boot should be enough for VxWorks to function under PIC mode.
>
>> I have an other (wired) question you may could help out.
>>
>> http://www.mouser.com/pdfdocs/Intel_Platform_Controller_Hub_EG20T_datasheet.pdf
>> (page 124)
>>
>> On my development board the uart_clk is connected to a oscillator and
>> everything works as expected.
>> But on the production devices the uart_clk is not connected and fsp
>> hangs with post code 0x2e.
>>
>
> I am not sure about the meaning of post code 0x2e. Jian has some
> working experience on Atom E6xx with U-Boot. Adding him.
>

0x2e == POST_PRE_MRC (arch/x86/include/asm/post.h)

>> Now I would like to change the initial mux settings to use usb_48mhz
>> but I am quite sure that I need
>> to have the pci bus and its devices initialised already in order to
>> change the CLKCFG register. Do you
>> think there is an other way of accessing this register like fixed
>> memory address etc?
>>
>
> Which register do you want to program for this uart_clk? If it's on
> the PCI configuration space, you can use PCI config APIs to program.
>

There a handful of registers I would need to program but all of them are
accessible via pic config space. E.g CLKCFG:

Size: 32-bit Default: 20000C00 Power Well: Core
Access PCI Configuration B:D:F D0:F0 Offset Start: Offset End: 500h 503h
            Memory Mapped I/O BAR: PKTHubCTLBASE Offset: 500h


As I need to program those registers before fsp_init I must setup the pci
bus by myself, change the register values and call fsb_init routine. Correct?

greets
--
Christian Gmeiner, MSc

https://soundcloud.com/christian-gmeiner


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