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author | Gabe Black <gblack@eecs.umich.edu> | 2009-10-30 00:44:55 -0700 |
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committer | Gabe Black <gblack@eecs.umich.edu> | 2009-10-30 00:44:55 -0700 |
commit | 3f722b991fcb33ca21330501960406a8a58e2be2 (patch) | |
tree | 69f446fd29600df013ae0695399a986c779f363b /src/sim/process.hh | |
parent | 25d932868998db26054910078721433ab430c836 (diff) | |
download | gem5-3f722b991fcb33ca21330501960406a8a58e2be2.tar.xz |
Syscalls: Make system calls access arguments like a stack, not an array.
When accessing arguments for a syscall, the position of an argument depends on
the policies of the ISA, how much space preceding arguments took up, and the
"alignment" of the index for this particular argument into the number of
possible storate locations. This change adjusts getSyscallArg to take its
index parameter by reference instead of value and to adjust it to point to the
possible location of the next argument on the stack, basically just after the
current one. This way, the rules for the new argument can be applied locally
without knowing about other arguments since those have already been taken into
account implicitly.
All system calls have also been changed to reflect the new interface. In a
number of cases this made the implementation clearer since it encourages
arguments to be collected in one place in order and then used as necessary
later, as opposed to scattering them throughout the function or using them in
place in long expressions. It also discourages using getSyscallArg over and
over to retrieve the same value when a temporary would do the job.
Diffstat (limited to 'src/sim/process.hh')
-rw-r--r-- | src/sim/process.hh | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/src/sim/process.hh b/src/sim/process.hh index 7922ce073..ab9d64cf3 100644 --- a/src/sim/process.hh +++ b/src/sim/process.hh @@ -325,7 +325,9 @@ class LiveProcess : public Process std::string getcwd() const { return cwd; } virtual void syscall(int64_t callnum, ThreadContext *tc); - virtual TheISA::IntReg getSyscallArg(ThreadContext *tc, int i) = 0; + + virtual TheISA::IntReg getSyscallArg(ThreadContext *tc, int &i) = 0; + virtual TheISA::IntReg getSyscallArg(ThreadContext *tc, int &i, int width); virtual void setSyscallArg(ThreadContext *tc, int i, TheISA::IntReg val) = 0; virtual void setSyscallReturn(ThreadContext *tc, |