[U-Boot] Is there any full story about how to take advantage FDT function ?
And how to configure the kernel to minimize the code modification ?
I am porting U-Boot and Linux to a new board with a MPC875 processor and two serial chips, and U-Boot runs well now. I hear that the FDT function can tell the kernel devices information more flexibly and reduce the code modification indirectly.
But I didn't find enough materials to make my head clear, so any tip is greatly appreciated.
Thanks.
Gao Ya'nan wrote:
And how to configure the kernel to minimize the code modification ?
I am porting U-Boot and Linux to a new board with a MPC875 processor and two serial chips, and U-Boot runs well now. I hear that the FDT function can tell the kernel devices information more flexibly and reduce the code modification indirectly.
But I didn't find enough materials to make my head clear, so any tip is greatly appreciated.
Thanks.
Hi Gao,
I'm not up on 8xx, but it may not have been pulled forward into the "powerpc" architecture (still "ppc"). The "powerpc" architecture switch is where linux/u-boot started using the FDT.
Best regards, gvb
Hi, Jerry.
2009/9/6 Jerry Van Baren gvb.uboot@gmail.com:
Gao Ya'nan wrote:
And how to configure the kernel to minimize the code modification ?
I am porting U-Boot and Linux to a new board with a MPC875 processor and two serial chips, and U-Boot runs well now. I hear that the FDT function can tell the kernel devices information more flexibly and reduce the code modification indirectly.
But I didn't find enough materials to make my head clear, so any tip is greatly appreciated.
Thanks.
Hi Gao,
I'm not up on 8xx, but it may not have been pulled forward into the "powerpc" architecture (still "ppc"). The "powerpc" architecture switch is where linux/u-boot started using the FDT.
I use U-Boot-V2009.8 and Linux-DENX-v2.6.30.3, and I can't find arch/ppc any more. So, I think FDT will work well in MPC8xx platform.
But I don't know how to use it, perhaps I shoud try the standard MPC885 configuration and dtb file.
Best regards, gvb
Thanks.
Best regards
Gao Ya'nan
On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
I'm not up on 8xx, but it may not have been pulled forward into the "powerpc" architecture (still "ppc"). The "powerpc" architecture switch is where linux/u-boot started using the FDT.
8xx is supported in arch/powerpc.
-Scott
2009/9/10 Scott Wood scottwood@freescale.com:
On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
I'm not up on 8xx, but it may not have been pulled forward into the "powerpc" architecture (still "ppc"). The "powerpc" architecture switch is where linux/u-boot started using the FDT.
8xx is supported in arch/powerpc.
Yes, I have add CONFIG_OF_LIBFDT and CONFIG_OF_BOARD_SETUP for the FDT support which is missing in U-Boot-v2009.08, and it works well, but I found none complete document on how to write a dts file and add special device in it.
Any tips? Thanks
Gao Ya'nan
-Scott
Gao Ya'nan wrote:
2009/9/10 Scott Wood scottwood@freescale.com:
On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
I'm not up on 8xx, but it may not have been pulled forward into the "powerpc" architecture (still "ppc"). The "powerpc" architecture switch is where linux/u-boot started using the FDT.
8xx is supported in arch/powerpc.
Yes, I have add CONFIG_OF_LIBFDT and CONFIG_OF_BOARD_SETUP for the FDT support which is missing in U-Boot-v2009.08, and it works well, but I found none complete document on how to write a dts file and add special device in it.
Any tips? Thanks
See Documentation/powerpc/booting-without-of.txt, Documentation/powerpc/dts-bindings, and the ePAPR specification for information on the content of device trees.
-Scott
2009/9/10 Scott Wood scottwood@freescale.com:
Gao Ya'nan wrote:
2009/9/10 Scott Wood scottwood@freescale.com:
On Sat, Sep 05, 2009 at 02:41:19PM -0400, Jerry Van Baren wrote:
I'm not up on 8xx, but it may not have been pulled forward into the "powerpc" architecture (still "ppc"). The "powerpc" architecture switch is where linux/u-boot started using the FDT.
8xx is supported in arch/powerpc.
Yes, I have add CONFIG_OF_LIBFDT and CONFIG_OF_BOARD_SETUP for the FDT support which is missing in U-Boot-v2009.08, and it works well, but I found none complete document on how to write a dts file and add special device in it.
Any tips? Thanks
See Documentation/powerpc/booting-without-of.txt, Documentation/powerpc/dts-bindings, and the ePAPR specification for information on the content of device trees.
I miss the later two, thanks for your tips.
Gao.
-Scott
participants (3)
-
Gao Ya'nan -
Jerry Van Baren -
Scott Wood