* ld.texinfo (Top): Document specific options of 68HC11 and 68HC12.

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Stephane Carrez 2004-08-02 20:03:41 +00:00
parent 48c2c0a6f3
commit 93fd097323
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@ -1,3 +1,7 @@
2004-08-02 Stephane Carrez <stcarrez@nerim.fr>
* ld.texinfo (Top): Document specific options of 68HC11 and 68HC12.
2004-08-01 Stephane Carrez <stcarrez@nerim.fr> 2004-08-01 Stephane Carrez <stcarrez@nerim.fr>
* scripttempl/elfm68hc12.sc: Align text, rodata and data section * scripttempl/elfm68hc12.sc: Align text, rodata and data section

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@ -152,6 +152,9 @@ section entitled ``GNU Free Documentation License''.
@ifset HPPA @ifset HPPA
* HPPA ELF32:: ld and HPPA 32-bit ELF * HPPA ELF32:: ld and HPPA 32-bit ELF
@end ifset @end ifset
@ifset M68HC11
* M68HC11/68HC12:: ld and the Motorola 68HC11 and 68HC12 families
@end ifset
@ifset TICOFF @ifset TICOFF
* TI COFF:: ld and the TI COFF * TI COFF:: ld and the TI COFF
@end ifset @end ifset
@ -1302,6 +1305,9 @@ This option is only supported on a few targets.
@ifset XTENSA @ifset XTENSA
@xref{Xtensa,, @command{ld} and Xtensa Processors}. @xref{Xtensa,, @command{ld} and Xtensa Processors}.
@end ifset @end ifset
@ifset M68HC11
@xref{M68HC11/68HC12,,@command{ld} and the 68HC11 and 68HC12}.
@end ifset
On some platforms, the @samp{--relax} option performs global On some platforms, the @samp{--relax} option performs global
optimizations that become possible when the linker resolves addressing optimizations that become possible when the linker resolves addressing
@ -2173,6 +2179,34 @@ subsystem version also.
@c man end @c man end
@ifset M68HC11
@subsection Options specific to Motorola 68HC11 and 68HC12 targets
@c man begin OPTIONS
The 68HC11 and 68HC12 linkers support specific options to control the
memory bank switching mapping and trampoline code generation.
@table @gcctabopt
@kindex --no-trampoline
@item --no-trampoline
This option disables the generation of trampoline. By default a trampoline
is generated for each far function which is called using a @code{jsr}
instruction (this happens when a pointer to a far function is taken).
@kindex --bank-window
@item --bank-window @var{name}
This option indicates to the linker the name of the memory region in
the @samp{MEMORY} specification that describes the memory bank window.
The definition of such region is then used by the linker to compute
paging and addresses within the memory window.
@end table
@c man end
@end ifset
@ifset UsesEnvVars @ifset UsesEnvVars
@node Environment @node Environment
@section Environment Variables @section Environment Variables
@ -4648,6 +4682,9 @@ functionality are not listed.
@ifset MSP430 @ifset MSP430
* MSP430:: @command{ld} and MSP430 * MSP430:: @command{ld} and MSP430
@end ifset @end ifset
@ifset M68HC11
* M68HC11/68HC12:: @code{ld} and the Motorola 68HC11 and 68HC12 families
@end ifset
@ifset TICOFF @ifset TICOFF
* TI COFF:: @command{ld} and TI COFF * TI COFF:: @command{ld} and TI COFF
@end ifset @end ifset
@ -4788,6 +4825,57 @@ not itself call any subroutines).
@raisesections @raisesections
@end ifclear @end ifclear
@ifset M68HC11
@ifclear GENERIC
@raisesections
@end ifclear
@node M68HC11/68HC12
@section @command{ld} and the Motorola 68HC11 and 68HC12 families
@cindex M68HC11 and 68HC12 support
@subsection Linker Relaxation
For the Motorola 68HC11, @command{ld} can perform these global
optimizations when you specify the @samp{--relax} command-line option.
@table @emph
@cindex relaxing on M68HC11
@item relaxing address modes
@command{ld} finds all @code{jsr} and @code{jmp} instructions whose
targets are within eight bits, and turns them into eight-bit
program-counter relative @code{bsr} and @code{bra} instructions,
respectively.
@command{ld} also looks at all 16-bit extended addressing modes and
transforms them in a direct addressing mode when the address is in
page 0 (between 0 and 0x0ff).
@item relaxing gcc instruction group
When @command{gcc} is called with @option{-mrelax}, it can emit group
of instructions that the linker can optimize to use a 68HC11 direct
addressing mode. These instructions consists of @code{bclr} or
@code{bset} instructions.
@end table
@subsection Trampoline Generation
@cindex trampoline generation on M68HC11
@cindex trampoline generation on M68HC12
For 68HC11 and 68HC12, @command{ld} can generate trampoline code to
call a far function using a normal @code{jsr} instruction. The linker
will also change the relocation to some far function to use the
trampoline address instead of the function address. This is typically the
case when a pointer to a function is taken. The pointer will in fact
point to the function trampoline.
@ifclear GENERIC
@lowersections
@end ifclear
@end ifset
@node ARM @node ARM
@section @command{ld}'s Support for Interworking Between ARM and Thumb Code @section @command{ld}'s Support for Interworking Between ARM and Thumb Code