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2002-01-19 Russell King <rmk@arm.linux.org.uk>
* fpa11.h - Add documentation
- remove userRegisters pointer from this structure.
- add new method to obtain integer register values.
* softfloat.c - Remove float128
* softfloat.h - Remove float128
* softfloat-specialize - Remove float128
* The FPA11 structure is not a kernel-specific data structure.
It is used by users of ptrace to examine the values of the
floating point registers. Therefore, any changes to the
FPA11 structure (size or position of elements contained
within) have to be well thought out.
* Since 128-bit float requires the FPA11 structure to change
size, it has been removed. 128-bit float is currently unused,
and needs various things to be re-worked so that we won't
overflow the available space in the task structure.
* The changes are designed to break any patch that goes on top
of this code, so that the authors properly review their changes.
1999-08-19 Scott Bambrough <scottb@netwinder.org>
* fpmodule.c - Changed version number to 0.95
* fpa11.h - modified FPA11, FPREG structures
* fpa11.c - Changes due to FPA11, FPREG structure alterations.
* fpa11_cpdo.c - Changes due to FPA11, FPREG structure alterations.
* fpa11_cpdt.c - Changes due to FPA11, FPREG structure alterations.
* fpa11_cprt.c - Changes due to FPA11, FPREG structure alterations.
* single_cpdo.c - Changes due to FPA11, FPREG structure alterations.
* double_cpdo.c - Changes due to FPA11, FPREG structure alterations.
* extended_cpdo.c - Changes due to FPA11, FPREG structure alterations.
* I discovered several bugs. First and worst is that the kernel
passes in a pointer to the FPE's state area. This is defined
as a struct user_fp (see user.h). This pointer was cast to a
FPA11*. Unfortunately FPA11 and user_fp are of different sizes;
user_fp is smaller. This meant that the FPE scribbled on things
below its area, which is bad, as the area is in the thread_struct
embedded in the process task structure. Thus we were scribbling
over one of the most important structures in the entire OS.
* user_fp and FPA11 have now been harmonized. Most of the changes
in the above code were dereferencing problems due to moving the
register type out of FPREG, and getting rid of the union variable
fpvalue.
* Second I noticed resetFPA11 was not always being called for a
task. This should happen on the first floating point exception
that occurs. It is controlled by init_flag in FPA11. The
comment in the code beside init_flag state the kernel guarantees
this to be zero. Not so. I found that the kernel recycles task
structures, and that recycled ones may not have init_flag zeroed.
I couldn't even find anything that guarantees it is zeroed when
when the task structure is initially allocated. In any case
I now initialize the entire FPE state in the thread structure to
zero when allocated and recycled. See alloc_task_struct() and
flush_thread() in arch/arm/process.c. The change to
alloc_task_struct() may not be necessary, but I left it in for
completeness (better safe than sorry).
1998-11-23 Scott Bambrough <scottb@netwinder.org>
* README.FPE - fix typo in description of lfm/sfm instructions
* NOTES - Added file to describe known bugs/problems
* fpmodule.c - Changed version number to 0.94
1998-11-20 Scott Bambrough <scottb@netwinder.org>
* README.FPE - fix description of URD, NRM instructions
* TODO - remove URD, NRM instructions from TODO list
* single_cpdo.c - implement URD, NRM
* double_cpdo.c - implement URD, NRM
* extended_cpdo.c - implement URD, NRM
1998-11-19 Scott Bambrough <scottb@netwinder.org>
* ChangeLog - Added this file to track changes made.
* fpa11.c - added code to initialize register types to typeNone
* fpa11_cpdt.c - fixed bug in storeExtended (typeExtended changed to
typeDouble in switch statement)
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