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Message #11783
Re: [PATCH] - Fix for compiling on ARM CPUs
On 11/25/2013 05:21 PM, Robert Yates wrote:
Two problems to fix in order to allow compiling for ARM.
The first was to add the proper "Boost::Context assembly wrapper" files
for ARM, and modify common/system/fcontext.s to include them. The files
'jump_arm_aapcs_elf_gas.S' and 'make_arm_aapcs_elf_gas.S' I acquired
from the boost_1_55_0.tar.bz2 download from http://www.boost.org/
The second parch is for a fake rdtsc() function in include/profile.h to
make the compiler happy. I'm not a c++ programmer so I don't actually
know what the right thing to do is, but I'm sure returning the number
'42' isn't it. ;-) There seems to be a cycle counter register built
into ARM CPUs similar to the TSC register in x86 CPUs, but reading it is
not trivial just google 'arm cycle counter' to see what I mean.
But with these two patches I'm able to compile under Arch linux ARM on
my Chromebook
(http://archlinuxarm.org/platforms/armv7/samsung/samsung-chromebook) and
it seems to be running well.
Both patches are against revision 4499 of the lp:kicad branch.
On 11/25/13 11:54, Maciej Sumiński wrote:
Thank you for sharing the solution. I have to admit that the ARM build
happened faster than I thought it will. Regarding rdtsc() - in fact, you
may return 42, but the proper function would be great. As the header
name says - it is only for execution time measurements and it is not
critical for the application operation. By the way - did not you have
any problems with OpenGL?
Kind regards,
Orson
I've done some more digging and this is what I've found.
Although there is a cycle counter built into ARM devices, you have to
have kernel level access to enable it and to enable permission for the
user-mode code to read the register. Apparently the Linux kernel does
not do this by default so in order to use it you would have to write
some init code into a kernel module or hack it directly into the kernel
to make cycle level profiling work in Kicad. That seems a bit too much
effort to go to for a little profiling.
References here:
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0211h/Bihcgfcf.html
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0344b/Bgbjjhaj.html
http://stackoverflow.com/questions/3247373/how-to-measure-program-execution-time-in-arm-cortex-a8-processor
Then sniffing around with grep I learned that rdtsc() is only being
called by prof_start() and prof_end() in profile.h, and depending on how
you call prof_start() determines whether the timing source rdtsc() or
get_tics() is used for profiling. (Also as an interesting aside it
would seem right now all instances of prof_start() are being called
"prof_start( &totalTime, false );" which means rdtsc() is never actually
being called at all.) All that being said it would seem that the
functions rdtsc() and get_tics() are at least somewhat interchangeable.
If you still want a working timing function when rdtsc() is called on an
ARM processor I would suggest just copying the get_tics() function's
code to the __arm__ version of the rdtsc() function. I'll go ahead and
attach a patch that does just that since it's at least a much less ugly
hack then the first patch I sent in, and it's just about within my
abilities as a person who doesn't really know much about programming in
C++.
Also I noticed there's another profile.h at common/profile.h that is an
exact duplicate of the one I've been working with at include/profile.h
Is there any chance that common/profile.h would ever be included instead
of include/profile.h, or is it just an oversight and should be removed?
Oh and as far as problems with OpenGL. The 3D display in pcbnew does not
work, when I try to use it I get a delay where the program does not
respond for a short time and then the 3D display window finally comes up
but there is no 3D image, just black where the image should be. Also in
pcbnew the default display canvas works fine, the Cairo canvas also
works but is much slower, and the OpenGL canvas does not work, there is
just black where the board should be displayed. I'm really not sure if
the accelerated graphics drivers are installed properly glxgears runs
but with a distorted image at about 90fps. I can send you the output
from glxinfo or glewinfo or whatever else if you're interested.
=== modified file 'include/profile.h'
--- include/profile.h 2013-09-18 17:56:37 +0000
+++ include/profile.h 2013-11-25 23:17:35 +0000
@@ -59,6 +59,17 @@
}
+// ARM version, no easy access to cycle counter on ARM so just use gettimeofday()
+#elif defined(__arm__)
+static inline uint64_t rdtsc()
+{
+ struct timeval tv;
+ gettimeofday( &tv, NULL );
+
+ return (uint64_t) tv.tv_sec * 1000000ULL + (uint64_t) tv.tv_usec;
+}
+
+
#elif defined(__powerpc__)
static __inline__ unsigned long long rdtsc()
{
=== modified file 'common/system/fcontext.s'
--- common/system/fcontext.s 2013-10-14 11:43:57 +0000
+++ common/system/fcontext.s 2013-11-25 13:02:52 +0000
@@ -33,6 +33,10 @@
#include "jump_x86_64_sysv_elf_gas.S"
#include "make_x86_64_sysv_elf_gas.S"
+ #elif __arm__
+ #include "jump_arm_aapcs_elf_gas.S"
+ #include "make_arm_aapcs_elf_gas.S"
+
#else
#error "Missing make_fcontext & jump_fcontext routines for this architecture"
#endif
=== added file 'common/system/jump_arm_aapcs_elf_gas.S'
--- common/system/jump_arm_aapcs_elf_gas.S 1970-01-01 00:00:00 +0000
+++ common/system/jump_arm_aapcs_elf_gas.S 2013-11-25 13:01:07 +0000
@@ -0,0 +1,76 @@
+/*
+ Copyright Oliver Kowalke 2009.
+ Distributed under the Boost Software License, Version 1.0.
+ (See accompanying file LICENSE_1_0.txt or copy at
+ http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************************
+ * *
+ * ------------------------------------------------------------- *
+ * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | *
+ * ------------------------------------------------------------- *
+ * | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c| 0x20| 0x24| *
+ * ------------------------------------------------------------- *
+ * | v1 | v2 | v3 | v4 | v5 | v6 | v7 | v8 | sp | lr | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 10 | | *
+ * ------------------------------------------------------------- *
+ * | 0x28| | *
+ * ------------------------------------------------------------- *
+ * | pc | | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 11 | 12 | | *
+ * ------------------------------------------------------------- *
+ * | 0x2c| 0x30| | *
+ * ------------------------------------------------------------- *
+ * | sp | size| | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | *
+ * ------------------------------------------------------------- *
+ * | 0x34| 0x38|0x3c| 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58 | *
+ * ------------------------------------------------------------- *
+ * | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 | s24 | s25 | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 23 | 24 | 25 | 26 | 27 | 28 | | *
+ * ------------------------------------------------------------- *
+ * | 0x5c| 0x60| 0x64| 0x68| 0x6c| 0x70| | *
+ * ------------------------------------------------------------- *
+ * | s26 | s27 | s28 | s29 | s30 | s31 | | *
+ * ------------------------------------------------------------- *
+ * *
+ * *****************************************************************/
+
+.text
+.globl jump_fcontext
+.align 2
+.type jump_fcontext,%function
+jump_fcontext:
+ stmia a1, {v1-v8,sp-lr} @ save V1-V8,SP-LR
+ str lr, [a1,#40] @ save LR as PC
+
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+ cmp a4, #0 @ test if fpu env should be preserved
+ beq 1f
+
+ mov a4, a1
+ add a4, #52
+ vstmia a4, {d8-d15} @ save S16-S31
+
+ mov a4, a2
+ add a4, #52
+ vldmia a4, {d8-d15} @ restore S16-S31
+1:
+#endif
+
+ mov a1, a3 @ use third arg as return value after jump
+ @ and as first arg in context function
+ ldmia a2, {v1-v8,sp-pc} @ restore v1-V8,SP-PC
+.size jump_fcontext,.-jump_fcontext
+
+/* Mark that we don't need executable stack. */
+.section .note.GNU-stack,"",%progbits
=== added file 'common/system/make_arm_aapcs_elf_gas.S'
--- common/system/make_arm_aapcs_elf_gas.S 1970-01-01 00:00:00 +0000
+++ common/system/make_arm_aapcs_elf_gas.S 2013-11-25 13:01:07 +0000
@@ -0,0 +1,79 @@
+/*
+ Copyright Oliver Kowalke 2009.
+ Distributed under the Boost Software License, Version 1.0.
+ (See accompanying file LICENSE_1_0.txt or copy at
+ http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************************
+ * *
+ * ------------------------------------------------------------- *
+ * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | *
+ * ------------------------------------------------------------- *
+ * | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c| 0x20| 0x24| *
+ * ------------------------------------------------------------- *
+ * | v1 | v2 | v3 | v4 | v5 | v6 | v7 | v8 | sp | lr | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 10 | | *
+ * ------------------------------------------------------------- *
+ * | 0x28| | *
+ * ------------------------------------------------------------- *
+ * | pc | | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 11 | 12 | | *
+ * ------------------------------------------------------------- *
+ * | 0x2c| 0x30| | *
+ * ------------------------------------------------------------- *
+ * | sp | size| | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | *
+ * ------------------------------------------------------------- *
+ * | 0x34| 0x38|0x3c| 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58 | *
+ * ------------------------------------------------------------- *
+ * | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 | s24 | s25 | *
+ * ------------------------------------------------------------- *
+ * ------------------------------------------------------------- *
+ * | 23 | 24 | 25 | 26 | 27 | 28 | | *
+ * ------------------------------------------------------------- *
+ * | 0x5c| 0x60| 0x64| 0x68| 0x6c| 0x70| | *
+ * ------------------------------------------------------------- *
+ * | s26 | s27 | s28 | s29 | s30 | s31 | | *
+ * ------------------------------------------------------------- *
+ * *
+ * *****************************************************************/
+
+.text
+.globl make_fcontext
+.align 2
+.type make_fcontext,%function
+make_fcontext:
+ mov a4, a1 @ save address of context stack (base) A4
+ sub a1, a1, #116 @ reserve space for fcontext_t at top of context stack
+
+ @ shift address in A1 to lower 16 byte boundary
+ @ == pointer to fcontext_t and address of context stack
+ bic a1, a1, #15
+
+ str a4, [a1,#44] @ save address of context stack (base) in fcontext_t
+ str a2, [a1,#48] @ save context stack size in fcontext_t
+ str a3, [a1,#40] @ save address of context function in fcontext_t
+
+ str a1, [a1,#32] @ save address in A4 as stack pointer for context function
+
+ adr a2, finish @ compute abs address of label finish
+ str a2, [a1,#36] @ save address of finish as return address for context function
+ @ entered after context function returns
+
+ bx lr
+
+finish:
+ @ SP points to same addras SP on entry of context function
+ mov a1, #0 @ exit code is zero
+ bl _exit@PLT @ exit application
+.size make_fcontext,.-make_fcontext
+
+/* Mark that we don't need executable stack. */
+.section .note.GNU-stack,"",%progbits
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