Re: solved: pmbr: Boot loader too large
never underestimate the human stupidity (mine in this case) nor of the boot. pmbr will load the whole partition, which was 1M, instead of the size of gptboot :-( reducing the size of the slice/partition fixed the issue. pmbr doesn't have room to be but so smart. It can't parse a filesystem, so it just loads a raw partition assuming that the partition is the boot loader. The 545k bit has to do with where it is loaded. The boot loader has to live in the lower 640k, but it starts at 0x7c00 (the address that the BIOS always loads boot loaders). The 545k limit comes from 640k - 0x7c00. This is a fundamental limit of the x86 BIOS architecture. Compared to the 15.5k that UFS leaves for boot2 it is worlds of space. thanks for the info. If the error message was clearer might have saved some time :-) Partition size too big instead of Boot loader too large btw, thanks to grep -r I was to find it came from pmbr.s ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
Re: solved: pmbr: Boot loader too large
hi, this is the output from gpart show: = 34 976773101 ada0 GPT (465G) 34 2048 1 freebsd-boot (1.0M) 20824194304 2 freebsd-ufs [bootme] (2.0G) 4196386 12582912 3 freebsd-swap (6.0G) 16779298 959993837 4 freebsd-zfs (457G) = 34 976773101 ada1 GPT (465G) 34 2048 1 freebsd-boot (1.0M) 20824194304 2 freebsd-ufs (2.0G) 4196386 12582912 3 freebsd-swap (6.0G) 16779298 959993837 4 freebsd-zfs (457G) I also did: gpart bootcode -b /boot/pmbr ada0 I'm trying to boot and get Boot loader too large not matter if I boot from disk or pxe. The pmbr is 512 bytes, so what causes it to overshoot? I don't know x86 assembler (nor want to :-), but the comment says: 545k should be enough so what's going on? never underestimate the human stupidity (mine in this case) nor of the boot. pmbr will load the whole partition, which was 1M, instead of the size of gptboot :-( reducing the size of the slice/partition fixed the issue. ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
Re: solved: pmbr: Boot loader too large
On Tuesday, January 22, 2013 6:42:22 am Daniel Braniss wrote: hi, this is the output from gpart show: = 34 976773101 ada0 GPT (465G) 34 2048 1 freebsd-boot (1.0M) 20824194304 2 freebsd-ufs [bootme] (2.0G) 4196386 12582912 3 freebsd-swap (6.0G) 16779298 959993837 4 freebsd-zfs (457G) = 34 976773101 ada1 GPT (465G) 34 2048 1 freebsd-boot (1.0M) 20824194304 2 freebsd-ufs (2.0G) 4196386 12582912 3 freebsd-swap (6.0G) 16779298 959993837 4 freebsd-zfs (457G) I also did: gpart bootcode -b /boot/pmbr ada0 I'm trying to boot and get Boot loader too large not matter if I boot from disk or pxe. The pmbr is 512 bytes, so what causes it to overshoot? I don't know x86 assembler (nor want to :-), but the comment says: 545k should be enough so what's going on? never underestimate the human stupidity (mine in this case) nor of the boot. pmbr will load the whole partition, which was 1M, instead of the size of gptboot :-( reducing the size of the slice/partition fixed the issue. pmbr doesn't have room to be but so smart. It can't parse a filesystem, so it just loads a raw partition assuming that the partition is the boot loader. The 545k bit has to do with where it is loaded. The boot loader has to live in the lower 640k, but it starts at 0x7c00 (the address that the BIOS always loads boot loaders). The 545k limit comes from 640k - 0x7c00. This is a fundamental limit of the x86 BIOS architecture. Compared to the 15.5k that UFS leaves for boot2 it is worlds of space. -- John Baldwin ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to freebsd-hackers-unsubscr...@freebsd.org
