Raise the limit for /boot/loader to be 550k. The IBM PC imposes a limit of 640k of RAM below 1MB, which is needed for real mode calls. BTX takes 40k of that. The BIOS takes some amount (25k seems a good "99% take less than or equal to this" estimate for that, though some systems consume more). Most typical setups need 25k of stack. This leaves 550k for code. We set the limit to 550,000 which gives about an extra 13,000 bytes of buffer for machines that whose setups use a little more stack or whose BIOS reserves a bit more... Add this derivation in the Makefile. Also recommend setting LOADERSIZE lower in /etc/src.conf when the loader has to run on a system whose BIOS takes up more space, or for a complex setup. Add a recipe for how to find how much RAM your BIOS uses as well (thanks to jhb@ for the trick). Network cards that boot via PXE and HBAs with their BIOS enabled are known to be large consumers of lomem space. Sponsored by: Netflix Reviewed by: jhb Differential Revision: https://reviews.freebsd.org/D36152 |
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.. | ||
boot0 | ||
boot0sio | ||
boot2 | ||
btx | ||
cdboot | ||
common | ||
gptboot | ||
gptzfsboot | ||
isoboot | ||
libfirewire | ||
libi386 | ||
loader | ||
loader_4th | ||
loader_lua | ||
loader_simp | ||
mbr | ||
pmbr | ||
pxeldr | ||
zfsboot | ||
boot.ldscript | ||
Makefile | ||
Makefile.inc |