Le 06/10/2022 à 22:45, Segher Boessenkool a écrit : > On Thu, Oct 06, 2022 at 06:38:00PM +0000, Christophe Leroy wrote: >> Le 06/10/2022 à 20:22, Segher Boessenkool a écrit : >>> Long ago I built kernels that fit together with the boot firmware and a >>> root fs (busybox+dropbear essentially) in 4MB, but I doubt we can get >>> close to that at all these days :-) >> >> 4MB, not easy. But 8M still achievable. Well our smaller board has 32M, >> we have thousands of it spread all over Europe and have to keep it up to >> date .... > > The smallest of these systems had 256MB RAM. This 4MB is flash ROM :-)
I fit Uboot + DTB + Kernel + Initramfs with klibc and mtdutils in a 2MB flash ROM. > >>> What is the overhead if you enable modules but do not use them, these >>> days? >> >> On the 8xx it is mainly the instruction TLB miss handler: > > I meant just an indicative code size number... 100 bytes, 100kB, 100MB, > or something like that :-) And, on 64 bit, which is what the question > was about! Ah, does the size really matters here ? I was thinking more in terms of performance when I made the comment. Christophe