iPXE and SCCM 2012 Task Sequence

[mcb30]

(2014-05-06 22:18)mcb30 Wrote:  Has your SCCM boot.wim file been modified exactly as per the instructions on http://ipxe.org/howto/sccm? (None of the steps on that page are optional; if any are missing then the result will not work.)

I've looked over my notes. There are parts of the SCCM codebase which do not correctly handle error conditions. In particular, there are places which do not check for NULL pointers being returned, and which will happily propagate such NULL pointers through to other code which, in turn, fails to sanity-check for NULL pointer values. You eventually get a crash in totally innocent-looking unrelated code because something random got trashed several thousand lines of code earlier in the boot sequence.

I tracked this down by copying windbg into the SCCM boot.wim and then debugging with the command-line debugger (cdb). (I think windbg itself wouldn't start due to large numbers of missing libraries, but cdb was quite happy.) I spent a lot of time debugging it and eventually came up with a precise set of steps to generate a wimboot-bootable SCCM image; the results are at http://ipxe.org/howto/sccm.

Michael