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pdp10-relocation.txt: add relocations for literals, remove :ifiw modifier, tweaks

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Mikael Pettersson
2020-02-09 19:20:47 +01:00
parent 41a26ca60a
commit 02a5818496
1 changed files with 30 additions and 9 deletions
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39
doc/pdp10-relocation.txt
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@@ -24,8 +24,8 @@ Relocation entries reside in section headers with
- sh_info equal to the section header index to which the relocations apply
- sh_link equal to the section header index of an associated symbol table
Section start addresses are associated with symbols of type STT_SECTION
and STB_LOCAL bindins. These symbols are used for relocation.
Section start addresses are associated with symbols having STT_SECTION type
and STB_LOCAL binding. These symbols are used for relocation.
Symbols with st_shndx SHN_ABS have absolute values not affected by relocation.
@@ -106,29 +106,50 @@ R_PDP10_GLOBAL_H 7 uint36 (S+A) >>u 2
(S+A) must be halfword-aligned.
The place, P, must be word-aligned.
R_PDP10_LITERAL_W 8 uint36 S+A
R_PDP10_LITERAL_H 9 uint18 S+A
R_PDP10_LITERAL_B 10 uint9 S+A
These produce a literal value of the indicated size.
(S+A) must fit in the destination without loss of precision.
The place, P, must be aligned to an integer multiple of the value size.
[TODO: extend with GOT, PLT, and TLS relocations]
Assembler Syntax
symbol+offset
Produces no relocation if the symbol is absolute.
opcode accumulator,@?symbol+offset(index)
Produces R_PDP10_IFIW, unless the symbol is absolute,
in which case the value is emitted as-is with no relocation.
opcode accumulator,symbol+offset(index)
opcode accumulator,:ifiw(symbol+offset)(index)
Produces R_PDP10_IFIW.
.long symbol+offset
.long :w(symbol+offset)
Produces R_PDP10_LOCAL_W when assembling for -mno-extended,
and R_PDP10_EFIW when assembling for -mextended.
If the symbol is absolute, produces the appropriately encoded
value with no relocation.
.long :b(symbol+offset)
Produces R_PDP10_LOCAL_B when assembling for -mno-extended,
and R_PDP10_GLOBAL_B when assembling for -mextended.
If the symbol is absolute, produces the appropriately encoded
value with no relocation.
.long :h(symbol+offset)
Produces R_PDP10_LOCAL_H when assembling for -mno-extended,
and R_PDP10_GLOBAL_H when assembling for -mextended.
If the symbol is absolute, produces the appropriately encoded
value with no relocation.
.long symbol+offset
Produces R_PDP10_LITERAL_W, unless the symbol is absolute,
in which case the value is emitted as-is with no relocation.
.hword symbol+offset
Produces R_PDP10_LITERAL_H, unless the symbol is absolute,
in which case the value is emitted as-is with no relocation.
.byte symbol+offset
Produces R_PDP10_LITERAL_B, unless the symbol is absolute,
in which case the value is emitted as-is with no relocation.
Names of relocation sections