From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Andreas_Bie=DFmann?= Date: Fri, 06 Jul 2012 10:19:49 +0200 Subject: [U-Boot] U-boot Porting In-Reply-To: <4FF628D2.20805@cavium.com> References: <4FF628D2.20805@cavium.com> Message-ID: <4FF69FA5.1020305@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Aaron Williams, On 06.07.2012 01:52, Aaron Williams wrote: > Hi Zahid, > > I am in charge of U-Boot for OCTEON MIPS. I have not pushed the changes > back upstream since the amount of code is enormous (over 430K lines of > code!). Granted, a huge percentage of that is from generated register > files but it is still a huge amount of code. Just the DRAM > initialization code is 9600 lines of code for DDR2 and DDR3 support. > > We also do things that no other architecture does with U-Boot such as we > always run in TLB mapped memory. The code is available under GPL but you > need to contact support at cavium.com. With the TLB mapping it no longer > matters where U-Boot is loaded in memory. The same U-Boot binary image > can start executing at any 64K flash boundary in the first 4MB of flash > (so we support the same image as a failsafe and standard bootloader), > any 4MB boundary in RAM (when booted over PCI or eJTAG) and out of L2 > cache (our top of trunk copies itself from flash to the L2 cache very > early on to speed up memory initialization). The TLB mapping also allows > U-Boot to be copied to the very top of memory since KSEG0 is rather > limited to only 256MB. This is essential since we can support many GB of > RAM which otherwise requires 64-bit addressing. > > I need to push some of my changes back upstream since I have added some > drivers for some temperature sensors, power monitors, fixed the AHCI > driver and added a few features over the standard U-Boot (such as > dynamically generated prompt support). I would really like to see the whole stuff in mainline in favor of out of tree patches maintained only inside Cavium. Mainline U-Boot may also benefit from your generic changes and you will get reviews for free. Best regards Andreas Bie?mann