Overlays - Revision history

Louist103: Cleanup rodata and bss wording

2021-12-12T20:42:50Z

Cleanup rodata and bss wording

2021-11-15T22:08:36Z

2018-02-26T08:39:07Z

‎Block Table

2018-01-18T07:01:34Z

2016-04-10T01:11:02Z

‎Relocation Entry Format

2016-03-29T00:32:51Z

‎Relocation Entry Format

2016-03-29T00:23:06Z

‎Overlay Tables: First link now contains the actor overlay table

2015-11-23T21:22:40Z

typo

2015-11-23T07:11:32Z

2015-11-23T04:49:54Z

slipped up

@@ Line 18: / Line 18: @@
 !Rodata block
 |style="text-align:center;"| Read-Only Data<br>(Constant variables)
-|Usually contains text used with the n64 debugging print function (0x80002130) and thus contains empty format strings.
+|Usually contains float literals, jump tables, and on the debug versions text used with the n64 debugging print function (0x80002130).
 |-
 !BSS block
-|style="text-align:center;"| Zero-Initialized Data
+|style="text-align:center;"| Uninitialized Data
-| Everything that has static allocation and is initialized to zero is kept within this section. The BSS block is created at run-time,  allocated immediately after the overlay's data
+| Uninitialized static and global data is initialized to zero at runtime and is kept within this section. Allocated immediately after the overlay's data
 |-
 !Relocation block

@@ Line 100: / Line 100: @@
 | R_MIPS_26 || 4 || jump target
 |-
-| R_MIPS_HI16 || 5 || lui/ori pair high 16 bits
+| R_MIPS_HI16 || 5 || lui/addiu pair high 16 bits
 |-
-| R_MIPS_LO16 || 6 || lui/ori pair low 16 bits
+| R_MIPS_LO16 || 6 || lui/addiu pair low 16 bits
 |}
-There are more relocation types defined by the standard, but these are the only ones OoT seems to actualize. R_MIPS_HI16 must always come before a R_MIPS_LO16.
+There are more relocation types defined by the standard, but these are the only ones Nintendo seems to actualize.
 '''O''' = Offset - relative to start of section '''s'''

@@ Line 84: / Line 84: @@
 int Offset; // & 00FF FFFF
 </pre>
 '''S''' = Section ID
@@ Line 91: / Line 92: @@
 = .bss
-'''T''' = Relocation Type
+'''T''' = MIPS ABI Relocation Type
-= 32 bit pointer
+{|class="wikitable"
-= jump target
+! Name || Value || Description
-= lui/ori pt. 1
+|-
-= lui/ori pt. 2
+| R_MIPS_32 || 2 || 32 bit pointer
-''(read program Macros below)''
+|-
 '''O''' = Offset - relative to start of section '''s'''
 [https://github.com/mzxrules/vg64tools/blob/master/n64/z_snippets/z_ovl_adapt.c Example implementation on 47-50]
@@ Line 120: / Line 120: @@
   ''>> is the symbol for a right bitshift operation''
   ''& in this context works on the bits instead of the truth values the operands produce (in both instances)''
 ==Custom Actors==

← Older revision		Revision as of 07:01, 18 January 2018
Line 1:		Line 1:
−	~~Overlays are~~ code ~~files which are loaded dynamically~~ into ram ~~due~~ to ~~an inadequate amount of physical memory to increase address space (for its respective target~~ system). ~~Therefor~~, ~~it is essentially~~ a memory management technique. Mind you, the follow figure is not an accurate representation in relation to Ocarina of Time, but is merely here to hopefully establish a spacial imprint as, of course, the purpose of it is identical:	+	In computer science, overlaying is the process transferring a block of code into ram, which allows a program to be larger than the system's available ram. As such, overlays are a block of code can be loaded dynamically into memory.
−
−	~~Instruction Larger~~
−	~~Address Space Address Space~~
−	~~+-----------+ +-----------+~~
−	~~\| misc \| \| \|~~
−	~~+-----------+ \| overlay 1 \|~~
−	~~\| Physical \| \| \|~~
−	~~\| RAM \| .----\| \|~~
−	~~+-----------+ \| +-----------+~~
−	~~\| Stack \| \| \| \|~~
−	~~+-----------+ \| \| \|~~
−	~~\| \| \| \| \|~~
−	~~\| Data \| \| .-\| overlay 2 \|~~
−	~~\| Structure \| \| \| \| \|~~
−	~~+-----------+ \| \| +-----------+~~
−	~~\| \| <-' \| \| \|~~
−	~~\| overlay \| <---' \| overlay 3 \|~~
−	~~\| section \|<-------\| \|~~
−	~~\| \|<--~~. ~~+-----------+~~
−	~~+-----------+ `---\| overlay 4 \|~~
−	~~\| misc \| \| \|~~
−	~~+-----------+ \| \|~~
−	~~+-----------+~~

	== Overlay Tables ==		== Overlay Tables ==

@@ Line 97: / Line 97: @@
 Relocation entries are one word (4 bytes) each and are composed of the following:
-.) Section ID<br>2.) Relocation type<br>3.) Offset (section relative)
+#  Section ID
 <tt>'''STOOOOOO'''</tt><br>
@@ Line 125: / Line 127: @@
 ''Note: There's room for more, but these are the only ones that OoT seems to actualize. ''
-[http://code.google.com/p/vg64tools/source/browse/n64/z_snippets/z_ovl_adapt.c Example implementation on 47-50]
+[https://github.com/mzxrules/vg64tools/blob/master/n64/z_snippets/z_ovl_adapt.c Example implementation on 47-50]
 ====Arithmetic to acquire above values====

@@ Line 25: / Line 25: @@
 == Overlay Tables ==
-{{For|a complete list of overlays|Overlay Tables| Actor Overlay Table}}
+{{For|a complete list of overlays|Overlay Tables}}
 == Format ==

← Older revision		Revision as of 21:22, 23 November 2015
Line 136:		Line 136:

	''>> is the symbol for a right bitshift operation''		''>> is the symbol for a right bitshift operation''
−	''& in this context works on the bits instead of the ~~true~~ values the operands produce (in both instances)''	+	''& in this context works on the bits instead of the truth values the operands produce (in both instances)''

@@ Line 11: / Line 11: @@
   |   Stack   |   |    |           |
   +-----------+   |    |           |
-  +           +   |    |           |
+  |           |   |    |           |
   |   Data    |   |  .-| overlay 2 |
   | Structure |   |  | |           |
@@ Line 51: / Line 51: @@
+|
 |}
 The last word in an overlay file contains a seek up value that points to the header for the overlay, which in turn points to the start of these blocks.
@@ Line 95: / Line 99: @@
 .) Section ID<br>2.) Relocation type<br>3.) Offset (section relative)
-<tt>'''stoooooo'''</tt><br>
+<tt>'''STOOOOOO'''</tt><br>
-'''s''' = Section ID
+'''S''' = Section ID
 = .text
 = .data
 = .rodata
 = .bss
-'''t''' = Relocation Type
+'''T''' = Relocation Type
 = 32 bit pointer
 = jump target
 = lui/ori pt. 1
 = lui/ori pt. 2
-The following Macros are from the ELF header on your computer that are used by OoT:
+'''O''' = Offset - relative to start of section '''s'''
   #define R_MIPS_32               2       /* Direct 32 bit         */
   #define R_MIPS_26               4       /* Direct 26 bit shifted */
@@ Line 116: / Line 125: @@
 ''Note: There's room for more, but these are the only ones that OoT seems to actualize. ''
-'''o''' = Offset - relative to start of section '''s'''
+ ''>> is the symbol for a right bitshift operation''
 ==Custom Actors==

@@ Line 135: / Line 135: @@
-[https://sites.google.com/site/deathbasketslair/zelda/majoras-mask/actors-and-overlays Deathbasket the benevolent says he will further elaborate for it's usage in Majora's Mask, and map functions the actors use.]
+[https://sites.google.com/site/deathbasketslair/zelda/majoras-mask/actors-and-overlays Deathbasket the benevolent says he will further elaborate for nOvl's usage in Majora's Mask, and map functions the actors use.]
 [[Category: Actors]]
 [[Category: Overlays| Overlays]]