From mboxrd@z Thu Jan 1 00:00:00 1970 To: Lokesh Kumar Cc: linuxppc-embedded@lists.linuxppc.org Subject: Re: Booting linux on MPC custom Board From: Wolfgang Denk Mime-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 In-reply-to: Your message of "Sun, 22 Jun 2003 13:32:17 EDT." <3439AB3A99ECD5409F3A52ACF814744D158D36@norcom2.norcom.net> Date: Sun, 22 Jun 2003 20:14:49 +0200 Message-Id: <20030622181454.C14E9C5FD7@atlas.denx.de> Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: In message <3439AB3A99ECD5409F3A52ACF814744D158D36@norcom2.norcom.net> you wrote: > > I have a custom board with a custom bootloader. The board is based on > MPC855T, with 8MB flash and 32MB RAM. > > I have to boot linux on this board. The issue I have is this - I have to use > the custom bootloader (to be able to boot older app as well). I think I have > two ways to go - > > 1. Custom bootloader enhanced to be able to load Linux. I do not think it is > faster approach given the time required. Maybe, maybe not. If you don't need any nice-to-have things it is very simple to boot Linux on any bootloader. > 2. Tell custom bootloader to load another bootloader like PPCBOOT (U-BOOT) > and then let it load Linux. Now, to go this route, I will have to run > PPCBOOT from RAM. Reading documentation of PPCBOOT, it says that it runs > from FLASH and relocates itself to RAM. > How can run PPCBOOT from RAM directly and then tell it to load > Linux?? Any HELP would be appreciated. Such a question will receive much better responses on the u-boot-users mailing list. In short: configure U-Boot to be linked at a specific RAM address, disable the RAM initialization code and other parts that have already been done by your bootloader, load it to the chosen address in RAM, and start it at offset 0x100. But there is probably a 3rd option: install U-Boot, and let it boot your "older apps". U-Boot supports more than just Linux. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de "In Christianity neither morality nor religion come into contact with reality at any point." - Friedrich Nietzsche ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/