Comment 8 for bug 1092265

So a little more investigation seems to suggest that chain.c32 now requires to specify a disk in order for it to localboot [1]. So it seems that we will have to add the parameter.

[1] https://kernel.googlesource.com/pub/scm/boot/syslinux/syslinux/+/9a276818187f7679cd453f5f1224202e96fc17fc%5E1..9a276818187f7679cd453f5f1224202e96fc17fc/