Kernel Data Area

The kernel data area is located at MCP absolute address 0. It is mapped through Memory Area zero of Environment Zero of Task #1.

The following areas of absolute memory are reserved for the purposes indicated.

Absolute
Memory Address
Purpose
00-39 Indirect Field Length
00-07 Undefined
08-15 Kernel Index Register One (KIX1)
16-23 Kernel Index Register Two (KIX2)
24-31 Kernel Index Register Three (KIX3)
32-37 Reserved
38-39 Result Storage for SDE, SDU,SZE,SZU
40-45 Kernel Stack Pointer
46-47 Kernel Breakpoint Mask
48 Halt Digit
49 Internal I/O Mask
50-71 Unused
72-81 Result Descriptor (R/D) Storage Area
82-85 Rev B: Reserved, Rev A: Task Number
86-93 Reserved
94-99 Kernel Interrupt Branch Address
100-5999 Reserved
6000-6007 Head of Ready List Pointer
6008-6015 Current Task Reinstate List Pointer
6016-6023 Interrupt Descriptor
6024-6031 Instruction Interrupt Cause Descriptor
6032-6039 Instruction Interrupt Cause Extension Descriptor
6040-6041 External Interrupt Cause Descriptor
6042-6043 Processor Number
6044-7999 Reserved
8000-8039 MCP Kernel Request Area