SITS PDUMP format - Revision history

Larsbrinkhoff: Some clarifications.

2022-10-13T12:06:07Z

Some clarifications.

Jnc: +cat, +links

2022-10-11T12:16:17Z

+cat, +links

Larsbrinkhoff: Description of ths SITS pure dump format.

2022-10-10T19:10:32Z

Description of ths SITS pure dump format.

New page

The [[SITS]] pure dump format is a core image file format amenable to paging. Most of the file is divided into 8Kbyte pages, suitable for [[PDP-11 memory management]].

The overall structure is: one page with the page table and other metadata, pages with contents for the address spaces, and a symbol table.

===Page table===

The first page in the file starts with a zero word.

Next comes the page table: 16 words for the instruction space, and 16 for the data space.

The words have this format:
{{16bit-header}}
| D=I || Absolute || colspan=2 | || File || || Private || Execute || Write || Read || colspan=3 | || colspan=3 | Page Length
{{16bit-bitout}}

After the page table comes four words: the starting address, the size of the symbol table in bytes, and the file position of the symbol table as a long word.

The rest of the page is empty.

===Content pages===

Only pages that are mapped and not absolute have content pages in the file. If a page is both in I and D spaces, the file only has the I copy.

Pages that are shorter than 8K are padded out to a page boundary.

===Symbol table===

After the last content page comes the symbol table. It does not have to end on a page boundar.

@@ Line 5: / Line 5: @@
 ===Page table===
-The first page in the file starts with a zero word.
+The first page in the file starts with a zero word.  This is what distinguishes it from an [[PDP-11 Absolute Loader|absolute loader]] file.
 Next comes the page table: 16 words for the instruction space, and 16 for the data space.
@@ Line 22: / Line 22: @@
 Only pages that are mapped and not [[absolute address|absolute]] have content pages in the file.  If a page is both in [[PDP-11 Memory Management|I and D spaces]], the file only has the I copy.
-Pages that are shorter than 8K are padded out to a page boundary.
+Pages that are shorter than 8K are padded out to a 8K boundary.
 ===Symbol table===

@@ Line 1: / Line 1: @@
-The [[SITS]] pure dump format is a core image file format amenable to paging.  Most of the file is divided into 8Kbyte pages, suitable for [[PDP-11 memory management]].
+The '''Pure Dump''' format of [[SITS]] is a [[main memory|core]] image file format amenable to [[virtual memory|paging]].  Most of the file is divided into 8Kbyte [[virtual memory|pages]], suitable for [[PDP-11 Memory Management]].
-The overall structure is: one page with the page table and other metadata, pages with contents for the address spaces, and a symbol table.
+The overall structure is: one page with the page table and other [[metadata]], pages with contents for the [[address space]]s, and a [[symbol table]].
 ===Page table===
@@ Line 14: / Line 14: @@
 {{16bit-bitout}}
-After the page table comes four words: the starting address, the size of the symbol table in bytes, and the file position of the symbol table as a long word.
+After the page table comes four words: the starting [[address]], the size of the symbol table in bytes, and the file position of the symbol table as a long word.
 The rest of the page is empty.
@@ Line 20: / Line 20: @@
 ===Content pages===
-Only pages that are mapped and not absolute have content pages in the file.  If a page is both in I and D spaces, the file only has the I copy.
+Only pages that are mapped and not [[absolute address|absolute]] have content pages in the file.  If a page is both in [[PDP-11 Memory Management|I and D spaces]], the file only has the I copy.
 Pages that are shorter than 8K are padded out to a page boundary.
@@ Line 26: / Line 26: @@
 ===Symbol table===
-After the last content page comes the symbol table.  It does not have to end on a page boundar.
+After the last content page comes the symbol table.  It does not have to end on a page boundary.