.SNOOP - snap memory on GCOS8.

Usage:

B:
   status = .snoop(kpx, segment, offset [, vector, words])

C:
   #equate _snoop .snoop
   int _snoop(int kpx, int segment, int offset,
              [void *vector, int words]);

Where:

kpx

is the program number or Known Process indeX of the program which owns the segment being snapped. There are two special values of "kpx".

0: This implies that it is a system segment.
-1: This implies that it is the current process, and avoids having to find your own process number.

segment

identifies the segment being snapped. It is divided into 's' and 'd' fields like the hardware segid.

s = 3 (06000 - 07777): The D field is the segment number in the system linkage segment (use SD.xxx symbols) or in the named KPX's Linkage segment. Note that for accommodation mode programs, 06000 is the ISR.
s=0, d < 1760 (0 - 01757): The 'd' field is an index into the process's PUSH. This is illegal for kpx=0, and odd values of 'd' will fail. Use the PH.xxx symbol.
s=0, d = 1760 -: This hardware illegal segid refers to the process's PUSH. This is not supported in the batch version.
s=0, d > 1760 (01761 - 01777): These are the hardware values for specific descriptor registers. The segment currently described by that register is used. Only .LSR may be used for KPX=0. .CTYP (01761) and .DSDR (01763) are always illegal. This feature is not supported in batch.

The referenced descriptor must describe a data, descriptor, or super segment (type 0, 1, 2, 3, 4 or 6).

offset

is the offset into the selected segment of the first word to be snapped.

vector

is the starting address in the current program where the snapped data is to be stored. If "words" is zero or omitted, then "vector" may be omitted or specified as zero. The default is zero.

words

specifies the number of words to be snapped. The default is zero.

status

will contain the value of the first addressed word if "words" is zero. If "words" is non-zero, "status" indicates whether the snap was successful. The following statuses may be returned in the lower 16 bits:

0: Successful. In this case, a residue count is returned in the upper 20 bits of "status". For most cases, you can simply use the upper 18 bits as a word residue.
1: Process busy.
2: Process is swapped (not in memory).
3: Non-existent process.
4: Process is busy snapping some other process.
5: Permissions denied.
6: Too many words to move.
7: Word offset out of bounds.
8: Illegal TYPE segment specified.
9: Bad segid. The 's' and 'd' fields are not meaningful for the selected KPX.
10: Bad argument. The PMME was given a bad output data segment.

Description:

.SNOOP allows the user to examine addresses outside the program's normal address space. Its use is privileged. A TSS user must be able to issue the Thinkage DRL T.PEEK. A batch program must be able to issue MME .EMMS.

Some of the above statuses are not issued when .SNOOP is used in batch. Instead, the program may simply abort or memory fault.

The TSS implementation of this function depends on Thinkage's DRL T.PEEK; thus .SNOOP cannot be used at sites that do not support this DRL and the corresponding PMME. This routine only functions under GCOS8. Consequently, in situations where the same information can be obtained with .PEEK, .PEEK should be used.

.SNOOP - snap memory on GCOS8.

Usage:

Where:

Description:

See Also: