This is groundwork for supporting multiple TCG contexts.
The naive solution here is to split code_gen_buffer statically
among the TCG threads; this however results in poor utilization
if translation needs are different across TCG threads.
What we do here is to add an extra layer of indirection, assigning
regions that act just like pages do in virtual memory allocation.
(BTW if you are wondering about the chosen naming, I did not want
to use blocks or pages because those are already heavily used in QEMU).
We use a global lock to serialize allocations as well as statistics
reporting (we now export the size of the used code_gen_buffer with
tcg_code_size()). Note that for the allocator we could just use
a counter and atomic_inc; however, that would complicate the gathering
of tcg_code_size()-like stats. So given that the region operations are
not a fast path, a lock seems the most reasonable choice.
The effectiveness of this approach is clear after seeing some numbers.
I used the bootup+shutdown of debian-arm with '-tb-size 80' as a benchmark.
Note that I'm evaluating this after enabling per-thread TCG (which
is done by a subsequent commit).
* -smp 1, 1 region (entire buffer):
qemu: flush code_size=83885014 nb_tbs=154739 avg_tb_size=357
qemu: flush code_size=83884902 nb_tbs=153136 avg_tb_size=363
qemu: flush code_size=83885014 nb_tbs=152777 avg_tb_size=364
qemu: flush code_size=83884950 nb_tbs=150057 avg_tb_size=373
qemu: flush code_size=83884998 nb_tbs=150234 avg_tb_size=373
qemu: flush code_size=83885014 nb_tbs=154009 avg_tb_size=360
qemu: flush code_size=83885014 nb_tbs=151007 avg_tb_size=370
qemu: flush code_size=83885014 nb_tbs=151816 avg_tb_size=367
That is, 8 flushes.
* -smp 8, 32 regions (80/32 MB per region) [i.e. this patch]:
qemu: flush code_size=76328008 nb_tbs=141040 avg_tb_size=356
qemu: flush code_size=75366534 nb_tbs=138000 avg_tb_size=361
qemu: flush code_size=76864546 nb_tbs=140653 avg_tb_size=361
qemu: flush code_size=76309084 nb_tbs=135945 avg_tb_size=375
qemu: flush code_size=74581856 nb_tbs=132909 avg_tb_size=375
qemu: flush code_size=73927256 nb_tbs=135616 avg_tb_size=360
qemu: flush code_size=78629426 nb_tbs=142896 avg_tb_size=365
qemu: flush code_size=76667052 nb_tbs=138508 avg_tb_size=368
Again, 8 flushes. Note how buffer utilization is not 100%, but it
is close. Smaller region sizes would yield higher utilization,
but we want region allocation to be rare (it acquires a lock), so
we do not want to go too small.
* -smp 8, static partitioning of 8 regions (10 MB per region):
qemu: flush code_size=21936504 nb_tbs=40570 avg_tb_size=354
qemu: flush code_size=11472174 nb_tbs=20633 avg_tb_size=370
qemu: flush code_size=11603976 nb_tbs=21059 avg_tb_size=365
qemu: flush code_size=23254872 nb_tbs=41243 avg_tb_size=377
qemu: flush code_size=28289496 nb_tbs=52057 avg_tb_size=358
qemu: flush code_size=43605160 nb_tbs=78896 avg_tb_size=367
qemu: flush code_size=45166552 nb_tbs=82158 avg_tb_size=364
qemu: flush code_size=63289640 nb_tbs=116494 avg_tb_size=358
qemu: flush code_size=51389960 nb_tbs=93937 avg_tb_size=362
qemu: flush code_size=59665928 nb_tbs=107063 avg_tb_size=372
qemu: flush code_size=38380824 nb_tbs=68597 avg_tb_size=374
qemu: flush code_size=44884568 nb_tbs=79901 avg_tb_size=376
qemu: flush code_size=50782632 nb_tbs=90681 avg_tb_size=374
qemu: flush code_size=39848888 nb_tbs=71433 avg_tb_size=372
qemu: flush code_size=64708840 nb_tbs=119052 avg_tb_size=359
qemu: flush code_size=49830008 nb_tbs=90992 avg_tb_size=362
qemu: flush code_size=68372408 nb_tbs=123442 avg_tb_size=368
qemu: flush code_size=33555560 nb_tbs=59514 avg_tb_size=378
qemu: flush code_size=44748344 nb_tbs=80974 avg_tb_size=367
qemu: flush code_size=37104248 nb_tbs=67609 avg_tb_size=364
That is, 20 flushes. Note how a static partitioning approach uses
the code buffer poorly, leading to many unnecessary flushes.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
The core of this patch is this change to tcg/tcg.h:
> -extern TCGContext tcg_ctx;
> +extern TCGContext tcg_init_ctx;
> +extern TCGContext *tcg_ctx;
Note that for now we set *tcg_ctx to whatever TCGContext is passed
to tcg_context_init -- in this case &tcg_init_ctx.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This adds the -dfilter support to linux-user. There is a minor
checkpatch complaint about formatting which I've ignored for aesthetic
reasons.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
We had a check using TARGET_VIRT_ADDR_SPACE_BITS to make sure
that the allocation coming in from the command-line option was
not too large, but that didn't include target-specific knowledge
about other restrictions on user-space.
Remove several target-specific hacks in linux-user/main.c.
For MIPS and Nios, we can replace them with proper adjustments
to the respective target's TARGET_VIRT_ADDR_SPACE_BITS definition.
For ARM, we had no existing ifdef but I suspect that the current
default value of 0xf7000000 was chosen with this in mind. Define
a workable value in linux-user/arm/, and also document why the
special case is required.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20170708025030.15845-3-rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Almost every user of cpu_generic_init() checks for
returned NULL and then reports failure in a custom way
and aborts process.
Some users assume that call can't fail and don't check
for failure, though they should have checked for it.
In either cases cpu_generic_init() failure is fatal,
so instead of checking for failure and reporting
it various ways, make cpu_generic_init() report
errors in consistent way and terminate QEMU on failure.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <1505318697-77161-3-git-send-email-imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
These days, many programs are including a bug-reporting address,
or better yet, a link to the project web site, at the tail of
their --help output. However, we were not very consistent at
doing so: only qemu-nbd and qemu-qa mentioned anything, with the
latter pointing to an individual person instead of the project.
Add a new #define that sets up a uniform string, mentioning both
bug reporting instructions and overall project details, and which
a downstream vendor could tweak if they want bugs to go to a
downstream database. Then use it in all of our binaries which
have --help output.
The canned text intentionally references http:// instead of https://
because our https website currently causes certificate errors in
some browsers. That can be tweaked later once we have resolved the
web site issued.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170803163353.19558-5-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The flags are arranged such that we can manipulate them either
a whole, or as individual bytes. The computation within
cpu_get_tb_cpu_state is now reduced to a single load and mask.
Tested-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Change malloc/strdup/free to g_malloc/g_strdup/g_free in
util/envlist.c.
Remove NULL checks for pointers returned from g_malloc and g_strdup
as they exit in case of failure. Also, update calls to envlist_create
to reflect this.
Free array and array contents returned by envlist_to_environ using
g_free in bsd-user/main.c and linux-user/main.c.
Update comments to reflect change in semantics.
Signed-off-by: Saurav Sachidanand <sauravsachidanand@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Shadow registers are part of the openrisc spec along with sr[cid], as
part of the fast context switching feature. When exceptions occur,
instead of having to save registers to the stack if enabled the CID will
increment and a new set of registers will be available.
This patch only implements shadow registers which can be used as extra
scratch registers via the mfspr and mtspr if required. This is
implemented in a way where it would be easy to add on the fast context
switching, currently cid is hardcoded to 0.
This is need for openrisc linux smp kernels to boot correctly.
Signed-off-by: Stafford Horne <shorne@gmail.com>
M profile doesn't implement ARM, and the architecturally required
behaviour for attempts to execute with the Thumb bit clear is to
generate a UsageFault with the CFSR INVSTATE bit set. We were
incorrectly implementing this as generating an UNDEFINSTR UsageFault;
fix this.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Programs run under qemu-ppc64 on an x86_64 host currently segfault
if they use pthread_create() due to the adjustment made to the NIP in
commit bd6fefe71c.
This patch changes cpu_loop() to set the NIP back to the
pre-incremented value before calling do_syscall(), which causes the
correct address to be used for the new thread and corrects the fault.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This avoids having to keep merging and extracting the flag from SR.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We need to handle EXCP_DEBUG and EXCP_INTERRUPT.
We need to send signals to the guest using queue_signal.
Signed-off-by: Richard Henderson <rth@twiddle.net>
"any" does not exist, therefore resulting in a misleading error message.
Reported-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170130145025.26475-1-david@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Alexander Graf <agraf@suse.de>
Cc: qemu-stable@nongnu.org
For v7M attempts to access a nonexistent coprocessor are reported
differently from plain undefined instructions (as UsageFaults of type
NOCP rather than type UNDEFINSTR). Split them out into a new
EXCP_NOCP so we can report the FSR value correctly.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1485285380-10565-8-git-send-email-peter.maydell@linaro.org
Add missing bits for qemu-user required for emulating Altera Nios2
userspace binaries.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Jeff Da Silva <jdasilva@altera.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Sandra Loosemore <sandra@codesourcery.com>
Cc: Yves Vandervennet <yvanderv@altera.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Message-Id: <20170118220146.489-4-marex@denx.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
HPPA is a (the) stack-grows-up target, and supporting that requires
rearranging how we compute addresses while laying out the initial
program stack. In addition, hppa32 requires 64-byte stack alignment
so parameterize that as well.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Update helper to set the throwing location in case of div-by-0.
Cleanup divX.w and add quad word variants of divX.l.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <rth@twidle.net>
[laurent: modified to clear Z on overflow, as found with risu]
Emulating LL/SC with cmpxchg is not correct, since it can
suffer from the ABA problem. However, portable parallel
code is written assuming only cmpxchg which means that in
practice this is a viable alternative.
Signed-off-by: Richard Henderson <rth@twiddle.net>
The exception is not emitted anymore.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1467054136-10430-30-git-send-email-cota@braap.org>
The exception is not emitted anymore.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twidle.net>
Message-Id: <1467054136-10430-29-git-send-email-cota@braap.org>
When we cannot emulate an atomic operation within a parallel
context, this exception allows us to stop the world and try
again in a serial context.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Version 2.0 of the semihosting specification introduces new trap
instructions for AArch32: HLT 0xF000 for A32 and HLT 0x3C for T32.
Implement these (in the same way we implement the existing HLT
semihosting trap for A64).
The old traps via SVC and BKPT are unaffected.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1476792973-18508-1-git-send-email-peter.maydell@linaro.org
The output string QEMU with "--version" is very long, it does
not fit into a normal line of a terminal window anymore. By
putting the copyright information on a separate line instead,
the output looks much nicer.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1475661284-30153-1-git-send-email-thuth@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Array mips_syscall_args[] determines number of arguments for each
syscall on Mips32. It wasn't updated with newer syscalls. Also,
preadv and pwritev have 5 arguments, not 6.
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Remove the notion of there being a single global array
of trace events, by introducing a method for registering
groups of events.
The module_call_init() needs to be invoked at the start
of any program that wants to make use of the trace
support. Currently this covers system emulators qemu-nbd,
qemu-img and qemu-io.
[Squashed the following fix from Daniel P. Berrange
<berrange@redhat.com>:
linux-user/bsd-user: initialize trace events subsystem
The bsd-user/linux-user programs make use of the CPU emulation
code and this now requires that the trace events subsystem
is enabled, otherwise it'll crash trying to allocate an empty
trace events bitmap for the CPU object.
--Stefan]
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-14-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Every time a vCPU is hot-plugged, it will "inherit" its tracing state
from the global state array. That is, if *any* existing vCPU has an
event enabled, new vCPUs will have too.
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147428970768.15111.7664565956870423529.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This will serve as the base for async_safe_run_on_cpu. Because
start_exclusive uses CPU_FOREACH, merge exclusive_lock with
qemu_cpu_list_lock: together with a call to exclusive_idle (via
cpu_exec_start/end) in cpu_list_add, this protects exclusive work
against concurrent CPU addition and removal.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make CPU work core functions common between system and user-mode
emulation. User-mode does not use run_on_cpu, so do not implement it.
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1470158864-17651-10-git-send-email-alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a mutex for the CPU list to system emulation, as it will be used to
manage safe work. Abstract manipulation of the CPU list in new functions
cpu_list_add and cpu_list_remove.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Convert pthread_mutex_t and pthread_cond_t to QemuMutex and QemuCond.
This will allow to make some locks and conditional variables common
between user and system mode emulation.
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1470158864-17651-7-git-send-email-alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There were a number of bugs in the implementation:
- The structure alignment was wrong for 64-bit.
- Also 64-bit only does RT signals.
- On 64-bit, we need to put a pointer to the (aligned) vector registers
in the frame and use it for restoring
- We had endian bugs when saving/restoring vector registers
- My recent fixes for exception NIP broke sigreturn in user mode
causing us to resume one instruction too far.
- Add VSR second halves
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Instead of assuming in queue_signal() that all callers are passing
a siginfo structure which uses the _sifields._sigfault part of the
union (and thus a si_type of QEMU_SI_FAULT), make callers pass
the si_type they require in as an argument.
[RV adjusted to apply]
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
64 bit user mode doesn't work for the e5500 core because the MSR_CM bit is
not set which enables the 64 bit mode for this MMU model. Memory addresses
are truncated to 32 bit, which results in "Invalid data memory access"
error messages. Fix it by setting the MSR_CM bit for this MMU model.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Display an exception number, generally defined as an hexadecimal
number (for instance, EXCP_HLT is 0x10001).
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Other archs don't do it, some programs catch signals just fine
and those dumps just clutter the output. Keep the dumps for cases
that aren't supposed to happen such as unknown codes.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The usermode "translate" code generates an error code value that
has the "is_write" bit set, which causes our switch/case to miss
and display "Invalid segfault errno" and a spurrious second state
dump. Fix it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently the -version command line argument prints a string ending
with "Copyright (c) 2003-2008 Fabrice Bellard". This is now some
eight years out of date; abstract it out of the several places that
print the string and update it to:
Copyright (c) 2003-2016 Fabrice Bellard and the QEMU Project developers
to reflect the work by all the QEMU Project contributors over the
last decade.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1470309276-5012-1-git-send-email-peter.maydell@linaro.org
Each vCPU gets a 'trace_dstate' bitmap to control the per-vCPU dynamic
tracing state of events with the 'vcpu' property.
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
[Changed const char *trace_file to char *trace_file since it's a
heap-allocated string that needs to be freed. This type is also
returned by trace_opt_parse() and used in vl.c.
--Stefan]
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 146860251784.30668.17339867835129075077.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This function needs to be converted to QOM hook and virtualised for
multi-arch. This rename interferes, as cpu-qom will not have access
to the renaming causing name divergence. This rename doesn't really do
anything anyway so just delete it.
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-Id: <69bd25a8678b8b31b91cd9760c777bed1aafb44e.1437212383.git.crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaitepeter@gmail.com>
This patch implements read and write access rules for Mips floating
point control and status register (FCR31). The change can be divided
into following parts:
- Add fields that will keep FCR31's R/W bitmask in procesor
definitions and processor float_status structure.
- Add appropriate value for FCR31's R/W bitmask for each supported
processor.
- Add function for setting snan_bit_is_one, and integrate it in
appropriate places.
- Modify handling of CTC1 (case 31) instruction to use FCR31's R/W
bitmask.
- Modify handling user mode executables for Mips, in relation to the
bit EF_MIPS_NAN2008 from ELF header, that is in turn related to
reading and writing to FCR31.
- Modify gdb behavior in relation to FCR31.
Signed-off-by: Thomas Schwinge <thomas@codesourcery.com>
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Emilio G. Cota