With the disklabel read logic in the sgi bootblocks, the 'a' partition no longer has to be the first partition on a disk, so the positioning remarks in the install notes and the installer seem outdated. The patch below removes them.
OK? Index: distrib/notes/sgi/install =================================================================== RCS file: src/distrib/notes/sgi/install,v retrieving revision 1.28 diff -u -p -r1.28 install --- distrib/notes/sgi/install 12 Aug 2015 06:47:16 -0000 1.28 +++ distrib/notes/sgi/install 5 Oct 2016 12:03:16 -0000 @@ -173,14 +173,7 @@ OpenBSDInstallPart4 OpenBSDInstallPart5 No partitions should overlap with the SGI Volume Header, which by - default will use the first 3134 sectors. Additionally, the 'a' - partition must be the first partition on the disk, immediately - following the SGI Volume Header. If the default Volume Header size is - used, the 'a' partition should be located at offset 3135. If the 'a' - partition is not located immediately after the Volume Header the boot - loader will not be able to locate and load the kernel. -dnl XXX Note that this is a #$%@ boot blocks limitation which should be fixed -dnl XXX by reading the real label in the boot blocks. + default will use the first 3134 sectors. OpenBSDInstallPart6({:-CD-ROM, NFS -:}) Index: distrib/sgi/ramdisk/install.md =================================================================== RCS file: src/distrib/sgi/ramdisk/install.md,v retrieving revision 1.39 diff -u -p -r1.39 install.md --- distrib/sgi/ramdisk/install.md 1 Jan 2016 00:47:51 -0000 1.39 +++ distrib/sgi/ramdisk/install.md 5 Oct 2016 12:03:16 -0000 @@ -110,12 +110,6 @@ The 'p' partition must be retained since this in turn contains the boot loader. No other partitions should overlap with the SGI Volume Header, which by default will use the first 3134 sectors. -Additionally, the 'a' partition must be the first partition on the disk, -immediately following the SGI Volume Header. If the default SGI Volume Header -size is used, the 'a' partition should be located at offset 3135. If the -'a' partition is not located immediately after the SGI Volume Header the -boot loader will not be able to locate and load the kernel. - Do not change any parameters except the partition layout and the label name. __EOT