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Diffstat (limited to 'gas/doc')
| -rw-r--r-- | gas/doc/c-arm.texi | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/gas/doc/c-arm.texi b/gas/doc/c-arm.texi index 1108014..dfb5f86 100644 --- a/gas/doc/c-arm.texi +++ b/gas/doc/c-arm.texi @@ -22,6 +22,7 @@ * ARM Floating Point:: Floating Point * ARM Directives:: ARM Machine Directives * ARM Opcodes:: Opcodes +* ARM Mapping Symbols:: Mapping Symbols @end menu @node ARM Options @@ -439,3 +440,32 @@ For information on the ARM or Thumb instruction sets, see @cite{ARM Software Development Toolkit Reference Manual}, Advanced RISC Machines Ltd. +@node ARM Mapping Symbols +@section Mapping Symbols + +The ARM ELF specification requires that special symbols be inserted +into object files to mark certain features: + +@table @code + +@cindex @code{$a} +@item $a +At the start of a region of code containing ARM instructions. + +@cindex @code{$t} +@item $t +At the start of a region of code containing THUMB instructions. + +@cindex @code{$d} +@item $d +At the start of a region of data. + +@end table + +The assembler will automatically insert these symbols for you - there +is no need to code them yourself. Support for tagging symbols ($b, +$f, $p and $m) which is also mentioned in the current ARM ELF +specification is not implemented. This is because they have been +dropped from the new EABI and so tools cannot rely upon their +presence. + |