User`s guide

Data Structures and Memory Layout
C.2 Restart Parameter Block
Table C–2 (Cont.) Restart Parameter Block Fields
(R11)+ Field Name Description
108: RPB$B_CTRLLTR Boot device controller number biased by 1. In
VAX/OpenVMS, this field is used by INIT (in
SYS) to construct the boot device’s controller
letter. A 0 implies this field has not been
initialized, else if initialized, A=1, B=2, etc.
(this field was added in Version 13 of VMB).
nn: The rest of the RPB is zeroed.
C.3 VMB Argument List
The VMB code will also initialize an argument list as shown in Table C–3 (the
address of the argument list is passed in the AP).
Table C–3 VMB Argument List
(AP)+ Field Name Description
04: VMB$L_FILECACHE Quadword filename.
0C: VMB$L_LO_PFN PFN of first page of physical memory (always 0,
regardless of where 128 Kbytes of "good" memory
starts).
10: VMB$L_HI_PFN PFN of last page of physical memory.
14: VMB$Q_PFNMAP Descriptor of PFN bitmap. First longword contains
count of bytes in bitmap. Second longword
contains physical address of bitmap. (Same rules
as for RPB$Q_PFNMAP listed above.)
1C: VMB$Q_UCODE Quadword.
24: VMB$B_SYSTEMID 48-bit (actually a quadword is allocated) booting
node address which is initialized when performing
a network boot. This field is copied from
the Target System Address parameter of the
parameters message. (The DECnet HIORD value
is added if the field was two bytes.)
2C: VMB$L_FLAGS Set as needed.
30: VMB$L_CI_HIPFN Cluster interface high PFN.
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Data Structures and Memory Layout C–9