> z/Linux was written for 31-bit addressing hardware. So the top bit is > always expected to be set in 32-bit data/31-bit addressing user mode.
That top bit ceases to be used by the hardware in BALR etc if the 32-bit program is run as AM64. So the only issue is whether any *code* goes to the effort of checking that top bit. I would be surprised if any C code has gone to that effort, which is the reference I was looking for. BFN. Paul. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
