On Fri, 2002-06-21 at 13:19, Eric W. Biederman wrote: > > I am also think about implementing a general purpose bootloader > > from scratch. Unfortunately, I crashed my HD last week so I have > > to redesign it all over again. > > Ouch! >
Yea, I also lost my preliminary clock gen stuff. > Actually that should work. We might have to double check that we ignore > unknown program segments but yes. > > > I got this problem because our in-house etherboot is getting > > bigger and bigger, and Linux/WinCE have different concept about > > "reserved memory". > > :) > The other solution is to get etherboot out of the way. There has been > some discussion about how to do that on the etherboot-developers list, > but it hasn't been implemented yet. > Does "get xxx out of the way" mean "dump it" or something else ?? > What kind of concept does WinCE have of reserved memory. My gut > impression is to just have etherboot move itself to the top of memory, > but if it gets to big, that may be an issue. > Actually nobody knows for sure. It seems that both WinCe 3.x and 4.X consider memory below 1 MB as reserved. From our experiments, WinCE 3.x and 4.x have very different memory layout above 1MB. Memory below 1 MB is already used by LinuxBIOS which left little room for Etherboot. This makes it very difficult to build a etherboot image such that it can be used for Linux and WinCE 3.x/4.x. So I was thinking if the .text and .rodata section can be made XIP in flash, we only need a few KBs for other sections in RAM. > For the systems I work with I have issues like: how do I make the full > 4GB of ram plugged into this machine available to the kernel. So I > really don't have a feel if consuming an extra 300k-400k at the top of > memory would be a problem. > > I currently have a solution in memtest86 that allows for arbitrary > relocation, by making the application a shared library. The problem > is I can't remove the useless strings for all of the global variables, > so it bloats this a little bit. It is still better than having two > copies of the application like memtest86 did. > I think putting etherboot at top of RAM is a good idea, the problem is how can we do this kind of PIC/Dynamic Relocatable stuff ?? Ollie
