From mboxrd@z Thu Jan 1 00:00:00 1970 From: York Sun Date: Mon, 10 Mar 2014 08:26:04 -0700 Subject: [U-Boot] [PATCH 1/3] powerpc/p1010rdb: SECURE BOOT- define CONFIG_SYS_RAMBOOT for NAND boot In-Reply-To: <8b80270d5e2f4dc88e58326f43f00532@DM2PR03MB415.namprd03.prod.outlook.com> References: <1390209926-10115-1-git-send-email-aneesh.bansal@freescale.com> , <1390255477.24905.305.camel@snotra.buserror.net> <680c371d651d49a08b33ddd4d01fb3bd@DM2PR03MB415.namprd03.prod.outlook.com> <20140127142223.DDF2538033A@gemini.denx.de> <7f771c64c5c44208b24e38c75e159f28@DM2PR03MB415.namprd03.prod.outlook.com> <20140128053539.DE87A3801D7@gemini.denx.de> <5316094D.8060504@freescale.com> <8720849b6fdc48aeaf2dcbdfd1905a12@DM2PR03MB415.namprd03.prod.outlook.com> <1394042423.2697.192.camel@snotra.buserror.net> <1394218633.32664.37.camel@snotra.buserror.net> <531A1777.80302@freescale.com> <8b80270d5e2f4dc88e58326f43f00532@DM2PR03MB415.namprd03.prod.outlook.com> Message-ID: <531DD98C.9010205@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 03/10/2014 02:14 AM, Bansal Aneesh-B39320 wrote: >> -----Original Message----- >> From: Sun York-R58495 >> Sent: Saturday, March 08, 2014 12:31 AM >> To: Bansal Aneesh-B39320 >> Cc: Wood Scott-B07421; Wolfgang Denk; u-boot at lists.denx.de; Gupta >> Ruchika-R66431 >> Subject: Re: [U-Boot] [PATCH 1/3] powerpc/p1010rdb: SECURE BOOT- >> define CONFIG_SYS_RAMBOOT for NAND boot >> >> On 03/07/2014 10:57 AM, Scott Wood wrote: >>> On Thu, 2014-03-06 at 03:24 -0600, Bansal Aneesh-B39320 wrote: >>>>> -----Original Message----- >>>>> From: Wood Scott-B07421 >>>>> Sent: Wednesday, March 05, 2014 11:30 PM >>>>> To: Bansal Aneesh-B39320 >>>>> Cc: Sun York-R58495; Wolfgang Denk; u-boot at lists.denx.de; Gupta >>>>> Ruchika-R66431 >>>>> Subject: Re: [U-Boot] [PATCH 1/3] powerpc/p1010rdb: SECURE BOOT- >>>>> define CONFIG_SYS_RAMBOOT for NAND boot >>>>> >>>>> On Tue, 2014-03-04 at 23:30 -0600, Bansal Aneesh-B39320 wrote: >>>>>> Yes, in case of secure boot from NAND, the DRAM is initialized by >>>>> the >>>>>> BootROM and complete u-boot image is copied from NAND to DRAM by >>>>>> the >>>>> BootROM. >>>>>> So, it should be called RAMBOOT. >>>>> >>>>> DRAM or SRAM? Having ROM initialize DDR is a bit scary. >>>>> >>>>> -Scott >>>>> >>>> It can be either DDR or SRAM. It is not hardcoded in BootROM to >> initialize DDR. >>>> This depends on the config words (CF_WORDS) in the CF_HEADER. >>>> The Boot ROM code parses the config words and programs the >> addresses >>>> with data values accordingly. The user may opt to initialize DDR >> and >>>> get the image copied onto DDR or configure CPC as SRAM and get the >> Image copied onto SRAM. >>>> On 1010, >>> >>> P1010? LS1010? Something else? >>> >>>> the CPC size is not big enough to accommodate the U-boot image. >>>> So, currently the CF_WORDS are for DDR to be initialized and copy >> the image on DDR. >>> >>> Generally if SPD is present, it should be used to init DDR rather >> than >>> using hardcoded values. If U-Boot doesn't fit in SRAM, you can use >>> SPL instead of hardcoded init. >> >> I agree with Scott on this point. Using hardcoded values totally skip >> DDR driver. You don't only lose the flexibility of various speeds, you >> also skip all workarounds implemented in DDR driver. >> >> York > Currently we are following the same approach which was there for SPI and SD on P1010 i.e hardcoded initialization of DDR in platforms like P1010, 9131/9132 using config words. > Understood. York