Adding Vipin to the thread as he has better knowledge on this than me. Vipin can you please add your comments here as well..
As far as I can remember for the ARM based SPEAr SoCs on which we worked in the past: - At the moment the DDR initialization code for various ARM SoCs in u-boot is scattered across ARCH directories: See examples of SPEAr (based on ARM926ejs) [1] and OMAP4 (ARmv7) [2] DDR drivers. - There is no unified driver model in place for DDR driver similar to what is available for eth/serial drivers and we need to formulate a DDR model (something using the suggested framework in [3]) so that the same DDR driver can be shared across PPC and ARM SoCs. References: [1] SPEAr DDR drivers for Denali MPMC - http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/cpu/arm926ejs/spear/start.S;h=7dbd5dbf99e8c6e216cc50e789ec7f103e0ecaea;hb=HEAD#l105 http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/cpu/arm926ejs/spear/spl.c;h=b550404352b8c04f2e5d5d71df41c750c07ab1a8;hb=HEAD#l69 http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/cpu/arm926ejs/spear/spr600_mt47h128m8_3_266_cl5_async.c;h=cc45ab7016b1658eceb545c959bb1b59f33c06c7;hb=HEAD#l12 [2] OMAP4 Elpida DDR drivers - http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/cpu/armv7/omap4/sdram_elpida.c;h=67a79261f778c6afab3d0e3870eac1e18cff8411;hb=HEAD http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/cpu/armv7/omap4/emif.c;h=e89032be75dc916891ccfd70c66e19c4b7b38839;hb=HEAD [3] UDM-cores.txt - http://git.denx.de/?p=u-boot.git;a=blob;f=doc/driver-model/UDM-cores.txt;h=4e1318871a8d9f7f6f329800d6394158e42f85dd;hb=HEAD Regards, Bhupesh > -----Original Message----- > From: u-boot-boun...@lists.denx.de [mailto:u-boot-boun...@lists.denx.de] > On Behalf Of MJ embd > Sent: Tuesday, September 17, 2013 10:37 PM > To: sun york-R58495 > Cc: u-boot@lists.denx.de > Subject: Re: [U-Boot] How do ARM platform initialize DDR? > > yes, I am using uboot for arndale board. > The code is written by samsung only and it is not static. > > The best option would be to have an eth / serial driver kind of arch > which all soc vendors can share. But ddr is scattered, in absence of > that, your point seems valid for fsl specific. > > -mj > > On 9/17/13, York Sun <york...@freescale.com> wrote: > > Dear MJ, > > > > Thanks for your reply. > > > > I don't see the file in my copy. Probably it is not merged yet? > > Anyway, you just confirmed what I found so far. Do you use static > > setting in dmc_init_ddr3.c? I mean does it adapt to different DDR > > speeds and modules (if applicable)? > > > > In my mind, I am thinking to restructure arch/powerpc/cpu/mpc8xxx/ddr/ > > to driver/ddr/fsl/ so the same driver can be shared as far as the DDR > > IP is the same (or similar). > > > > York > > > > > > On 09/17/2013 09:34 AM, MJ embd wrote: > >> Hi York, > >> > >> There is no generic driver. AFAIK. Having worked on both mpc85xx and > >> ARM > >> > >> I can tell you about samsung 5250. There are 2 uboots (one spl and > >> other main). > >> In case of sd/mmc boot the internal rom copies the spl uboot to iRAM > >> and the spl boot loader initialises the DDR3. > >> > >> you can check for board/samsung/smdk5250/dmc_init_ddr3.c > >> > >> -Regards > >> mj > >> > >> On 9/17/13, York Sun <york...@freescale.com> wrote: > >>> Albert, > >>> > >>> Pardon me if this is a dumb question. I have been working on powerpc > >>> platforms in the past. Now we (the developers I work with) are > >>> exploring ARM cores. I am searching how memory is initialized and > >>> found different solutions. Some platforms have memory ready before > >>> u-boot even starts, some simply write to a set of registers. I > >>> understand many platforms don't share the IP of DDR controller. I am > >>> wondering if there is generic DDR driver used by many ARM platforms, > >>> like the one we have for powerpc/mpc85xx SoCs. > >>> > >>> Regards, > >>> > >>> York > >>> > >>> _______________________________________________ > >>> U-Boot mailing list > >>> U-Boot@lists.denx.de > >>> http://lists.denx.de/mailman/listinfo/u-boot > >>> > >> > >> > > > > > > > > > -- > -mj > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot