The YAMON license agreement is here which essentially says its GPL but read this anyway ... http://www.mips.com/LicenseMapper/Yamon_license The YAMON source code is here ... http://www.mips.com/content/Products/SoftwareTools/yamon Last time I read it the YAMON porting guide doc included with this distribution was kinda weak. That is, it does not explicitly tell you which files to change and so on compared to something like Wind River's porting guide for vxworks which is very explicit and detailed. But hey vxworks is a commercial product and this is free code. ;-) If you've ported a boot loader before you know the usual things you have to change (e.g. exception handlers, memory map specific stuff, device drivers, memory initialization, etc). The porting guide is not very explicit about which files each of these items is located in. So last time I ported YAMON I simply walked thru the code starting from ./yamon/arch/reset/bootvector/reset.S and modified what I needed to as I hit code that needed to change. You'd end up doing this anyway for bringup debugging. In most cases a LOT of code will be reusable because YAMON detects what core you have etc. So the amount of code you need to add/change is dependent on how close your target hardware is to what's already supported. There are other boot loaders available you can use like U-boot, Redboot, PMON, etc. The knock on YAMON is that its much bigger than these other loaders. That's because guys who originally wrote it chose not to use 'ifdefs' and conditional compiles for all the variants. So you get code linked in for all the variations (even though that code is not used) and it jumps to correct routines depending on your architecture. Makes the maintenance easier I guess. Not really meant to be used as a production bootrom in products but is used for eval boards. -earlm -----Original Message----- From: Jun Sun [mailto:jsun@mvista.com] Sent: Thursday, October 09, 2003 11:02 AM To: Adeel Malik Cc: linux-mips@linux-mips.org; jsun@mvista.com Subject: Re: YAMON Source code modification On Thu, Oct 09, 2003 at 03:46:19PM +0500, Adeel Malik wrote: > We want to port and 'run' YAMON to our own MIPS-based Development Board. Can > someone tell me what changes are necessary in the YAMON source code so that > it works on our board ?. > Regards, > ADEEL MALIK, > Actually is YAMON code freely available? Can someone from MIPS confirm that and perhaps point to the downloading place? Many people have asked me about this in the past ... Jun
