2 Linux for IBM System z9 and IBM zSeries
1.1 The zSeries and System z9 servers
The IBM Eserver zSeries and System z9 are based on z/Architecture - the next
step in the evolution from the System/360 to the System/370, System/370
extended architecture (370-XA), Enterprise Systems Architecture/370
(ESA/370), and Enterprise Systems Architecture/390 (ESA/390).
1.2 The central processing complex
This section describes the central processing complex.
1.2.1 Processing units
All processor units (PUs) are physically the same. At Power-on Reset (POR),
distinct microcode loaded in the PU determines its processor type:
Central Processor (CP)
CPs are enabled to execute any operation system available on zSeries
(including z/OS, z/VM, Linux, VSE, and TPF). ...