how can one compile .vhd under ghdl? - compilation

My first question : I wonder how you compile your vhdl file under ghdl ?
In c/c++, we use
-Werror
-Wunused-variable
-Wunused-value
-Wunused-function
-Wfloat-equal -Wall
.My second question : are there a way one can use ghdl with those things ?

The user manual for GHDL would be a good starting point, specifically sections 3.1 (building) and 3.4 (warnings).
It is difficult to compare a set of C/C++ compiler flags to that of a VHDL compiler, but there may be some similar functionality between them, such as warnings become errors and alerting the user to unused design components. For example (from the documentation):
--warn-unused
Emit a warning when a subprogram is never used.
--warn-error
When this option is set, warnings are considered as errors.

I have a nice example for makefile and GHDL:
"...Recently I added a makefile for this project. It is done based on the example c code interface for GHDL and IP TTL filter using VHDL. The makefile is described at makefile..."
http://bknpk.ddns.net/my_web/IP_STACK/start_1.html
and
"
VHDL IP Stack Makefile
This is a makefile for IP stack project.
#variables
CC = gcc
CFLAGS = -c -g
#-MD
SHELL := /bin/bash
GG = ghdl
GG_LIB = --ieee=synopsys --workdir=work
AFLAGS = -a --work=work
IFLAGS = -e
EFLAGS = -m -Wl,g_rand.o
..."
http://bknpk.ddns.net/my_web/IP_STACK/ip_stack_makefile.html

Related

What is the signification of LDFLAGS

I'm trying to compile AODV for ARM linux. I use a SabreLite as a board with kernel version 3.0.35_4.1.0. It's worth mention that i'm using openembedded to create my Linux Distribution for my board.
The AODV source code (http://sourceforge.net/projects/aodvuu/) has a README file which give some indications on how to install it on ARM as stated a bit here.
(http://w3.antd.nist.gov/wctg/aodv_kernel/kaodv_arm.html).
I was able to upgrade the makefile in order to be used with post 2.6 kernel version ( as stated above, i have the 3.0.35_4.1.0 kernel version).
So, basically, what i am trying to do is that i have to create a module (let's say file.ko) and then load it into the ARM (with insmod file.ko command).
To do that, i am using a cross compiler which some values are stated below:
echo $CC :
arm-oe-linux-gnueabi-gcc -march=armv7-a -mthumb-interwork -mfloat-abi=hard -mfpu=neon -mtune=cortex-a9 --sysroot=/usr/local/oecore-x86_64/sysroots/cortexa9hf-vfp-neon-oe-linux-gnueabi
echo $ARCH=arm
echo $CFLAGS: O2 -pipe -g -feliminate-unused-debug-types
echo $LD :
arm-oe-linux-gnueabi-ld --sysroot=/usr/local/oecore-x86_64/sysroots/cortexa9hf-vfp-neon-oe-linux-gnueabi
echo $LDFLAGS :
-Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -Wl,--as-needed
when i launch "make command", i get the following errors:
LD [M] /home/scof/script_emulation/AODV/aodv-uu/lnx/kaodv.o
arm-oe-linux-gnueabi-ld: unrecognized option '-Wl,-O1'
arm-oe-linux-gnueabi-ld: use the --help option for usage information
It states that there is something wrong with the linker. This linker comes from the cross compilation tools and i normally shouldn't touch it.
Anyway, to get this above errors fixed, i try to withdraw the LDFLAGS like this:
export LDFLAGS='',
and after this, the make command works and i get the module kaodv.ko. But when i insert it into my ARM to check, it does not work. It actually freeze my terminal
So my question is, do i have to specify the LDFLAGS when compiling ? Does withdrawing LDFLAGS can have impact on the generated kernel module.
Actually, i try to understand where might be the problem and the only thing that come to me is that may be i should not change manually the LDFLAGS. But if i don't change de LDFLAGS, i get the unrecognized option error.
My second question related to that is, what are the possibly value of LDFLAGS
in ARM compilation
Thanks !!
echo $LDFLAGS : -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -Wl,--as-needed
There are two common methods of invoking the linker in a GCC-based toolchain. One is to do it directly, but another is to use GCC as a front end to invoke the linker, rather than invoke it directly. When doing this, options intended for the linker are prefixed with -Wl, so that GCC knows to pass them through rather than interpret them itself.
In your case the error message from LD itself
arm-oe-linux-gnueabi-ld: unrecognized option '-Wl,-O1'
Indicates that your build system is passing LDFLAGS directly to the linker, and not by way of GCC.
Therefore, you should remove the -Wl, prefix and your LDFLAGS would instead be
-O1 --hash-style=gnu --as-needed --as-needed
(the duplication of the last argument is probably pointless but benign)
-O1 is an option that tells the linker to optimize. I believe it something new, and your linker may be slightly out of date. Try removing -Wl,-O1, it should still work.

How to (cross-)compile to both ARM hard- and soft-float (softfp) with a single GCC (cross-)compiler?

I'd like to use a single (cross-)compiler to compile code for different ARM calling conventions: since I always want to use floating point and NEON instructions, I just want to select the hard-float calling convention or the soft-float (softfp) calling convention.
My compiler defaults to hard-float, but it supports both architectures that I need:
$ arm-linux-gnueabihf-gcc -print-multi-lib
.;
arm-linux-gnueabi;#marm#march=armv4t#mfloat-abi=soft
$
When I compile with the default parameters:
$ arm-linux-gnueabihf-g++ -Wall -o hello_world_armhf hello_world.cpp
It succeeds without any errors.
If I compile with the parameters returned by -print-multi-lib:
$ arm-linux-gnueabihf-g++ -marm -march=armv4t -mfloat-abi=soft -Wall -o hello_world hello_world.cpp
It again compiles without error (By the way, how can I test that the resultant code is hard- or soft-float?)
Unfortunately, if I try this:
$ arm-linux-gnueabihf-g++ -march=armv7-a -mthumb-interwork -mfloat-abi=softfp -mfpu=neon -Wall -o hello_world hello_world.cpp
[...]/gcc/bin/../lib/gcc/arm-linux-gnueabihf/4.7.3/../../../../arm-linux-gnueabihf/bin/ld: error: hello_world uses VFP register arguments, /tmp/ccwvfDJo.o does not
[...]/gcc/bin/../lib/gcc/arm-linux-gnueabihf/4.7.3/../../../../arm-linux-gnueabihf/bin/ld: failed to merge target specific data of file /tmp/ccwvfDJo.o
collect2: error: ld returned 1 exit status
$
I've tested some other permutations of the parameters, but it seems that anything other than the combination shown by -print-multi-lib results in an error.
I've read ARM compilation error, VFP registered used by executable, not object file but the problem there was that some parts of the binary were soft- and some were hard-float. I have a single C++ file to compile...
What parameter(s) I miss to be able to compile with -march=armv7-a -mthumb-interwork -mfloat-abi=softfp -mfpu=neon?
How is it possible that the error is about VFP register arguments while I explicitly have -mfloat-abi=softfp in the command line which prohibits VFP register arguments?
Thanks!
For the records, hello_world.cpp contains the following:
#include <iostream>
int main()
{
std::cout << "Hello, world!" << std::endl;
return 0;
}
You need another compiler with corresponding multilib support.
You can check multilib support with next command.
arm-none-eabi-gcc -print-multi-lib
.;
thumb;#mthumb
fpu;#mfloat-abi=hard
armv6-m;#mthumb#march=armv6s-m
armv7-m;#mthumb#march=armv7-m
armv7e-m;#mthumb#march=armv7e-m
armv7-ar/thumb;#mthumb#march=armv7
cortex-m7;#mthumb#mcpu=cortex-m7
armv7e-m/softfp;#mthumb#march=armv7e-m#mfloat-abi=softfp#mfpu=fpv4-sp-d16
armv7e-m/fpu;#mthumb#march=armv7e-m#mfloat-abi=hard#mfpu=fpv4-sp-d16
armv7-ar/thumb/softfp;#mthumb#march=armv7#mfloat-abi=softfp#mfpu=vfpv3-d16
armv7-ar/thumb/fpu;#mthumb#march=armv7#mfloat-abi=hard#mfpu=vfpv3-d16
cortex-m7/softfp/fpv5-sp-d16;#mthumb#mcpu=cortex-m7#mfloat-abi=softfp#mfpu=fpv5-sp-d16
cortex-m7/softfp/fpv5-d16;#mthumb#mcpu=cortex-m7#mfloat-abi=softfp#mfpu=fpv5-d16
cortex-m7/fpu/fpv5-sp-d16;#mthumb#mcpu=cortex-m7#mfloat-abi=hard#mfpu=fpv5-sp-d16
cortex-m7/fpu/fpv5-d16;#mthumb#mcpu=cortex-m7#mfloat-abi=hard#mfpu=fpv5-d16
https://stackoverflow.com/questions/37418986/how-to-interpret-the-output-of-gcc-print-multi-lib
How to interpret the output of gcc -print-multi-lib
With this configuration gcc -mfloat-abi=hard not only will build your files using FPU instructions but also link them with corresponding libs, avoiding "X uses VFP register arguments, Y does not" error.
The above-mentioned -print-multi-lib output produced by gcc with this patch and --with-multilib-list=armv6-m,armv7,armv7-m,armv7e-m,armv7-r,armv7-a,cortex-m7 configuration option.
If you are interested in building your own gcc with Cortex-A series multilib support, just use --with-multilib-list=aprofile configuration option for any arm*-*-* target without any patches (at list with gcc-6.2.0).
As per Linaro FAQ if your compiler prints arm-linux-gnueabi;#marm#march=armv4t#mfloat-abi=soft then you can only use -march=armv4t. If you want to use -march=armv7-a you need to build compiler yourself.
Following link could be helpful in building yourself GCC ARM Builds

(g)make subroutine or procedure?

I have a (g)make script that covers a lot of microcontroller targets. A sequence of if blocks test for the various targets and set (or append) a lot of variables.
ifeq ($(CHIP),lpc1114fn28)
CORE_FLAGS := -mcpu=cortex-m0 -mthumb
CORE_FLAGS += -nostartfiles -fno-exceptions
CORE_CPP_FLAGS += -fno-threadsafe-statics -fno-use-cxa-get-exception-ptr
XTAL := 12000000
. . .
endif
There is a lot of duplication, which I'd like to factor out. I tried
define Cortex-M0 =
CORE_FLAGS := -mcpu=cortex-m0 -mthumb
CORE_FLAGS += -nostartfiles -fno-exceptions
endef
ifeq ($(CHIP),lpc1114fn28)
$(eval $(Cortex-M0))
CORE_CPP_FLAGS += -fno-threadsafe-statics -fno-use-cxa-get-exception-ptr
XTAL := 12000000
. . .
endif
But this does not seem to work. Is there a way to execute a subroutine-like construct that can contain multiple lines? I know I could use include files but I'd like to keep everything in one file.
If this isn't working then most likely your version of GNU make is older than 3.82. The syntax define VARIABLE = was introduced in that version; older versions don't allow you to use the assignment operator (=, :=, etc.) If make sees it there it will assign a variable named, literally, VARIABLE = (or in your case, Cortex-M0 =).
Remove the = at the end of the define line and it will work with older versions of GNU make.
Remember that the online version of the manual describes the latest version of GNU make; if you're not using that version, you should be careful that the version you're using supports the features you want. It's always safest to read the version of the manual that is provided to you along with the package of GNU make that you are using: whether it's your package manager or you downloaded it from somewhere yourself.
may be this:
ifeq ($(CHIP),lpc1114fn28)
$(eval $(call Cortex-M0))

Error: bad value for -march= switch

I wrote a Makefile and I can't get it to work. I have an option which is supposed to select which processor to compile to. However, when I run make from the commandline it says:
tandex#tandex-P-6860FX:~/emulators/nintendo sdks/3DS SDK [HomeBrew]$ make
gcc -march=arm7tdmi -static -fexceptions -fnon-call-exceptions -fstack-check test.c -c
test.c:1:0: error: bad value (arm7tdmi) for -march= switch
make: *** [ALL] Error 1
But in the man pages for gcc, it states that arm7tdmi is a permissible value. Am I missing something?
Makefile:
#3DS Compilation Makefile (c) TanDex (TEQ)RunawayFreelancers
#
#Version 0.99 (Alpha) For *nix Devices
#
#Please Check Back Soon for 3rd SDK
#SELECT THE COMPILER TO USE! GCC RECOMMENDED!
#FOR SANITY SAKE, USE C FILES WITH GCC AND CPP FILES WITH G++
CC=gcc
#CC=g++
#OBJECTCOPY REFERENCE, DO NOT REMOVE
OBJC=objcopy
OBJREFS= -O Binary
#SELECT THE PROCESSOR TO TUNE IT TO. ARMV7 (Nintendo DS) or ARMV9(Nintendo DS
(Graphical Support))
#or ARM11 Core ARM1176JZ-S and ARM1176JZF-S (3DS Processor? Not Sure if Correct. Try
and see if they Work?)
#
#NOTE: DS GAMES REQUIRE BOTH A ARM7 AND ARM9 BINARY. RUN THIS TWICE (ONCE FOR EACH)
#
#UNCOMMENT FOR PROCESOR
PROCESSOR=arm7tdmi
#PROCESSOR=arm946e-s
#PROCESSOR=arm1176jz-s
#PROCESSOR=arm1176jzf-s
#FILES
#
#PLACE ALL OF THE FILES HERE, THAT ARE BEING COMPILED!
FILES=test.c
#SET BIN FILE NAME BASED ON PROCESSOR SELECTED
ifeq($(PROCESSOR),arm7tdmi)\
NAME=ARM7.BIN
ifeq($(PROCESSOR), arm946e-s)\
NAME=ARM9.BIN
ifeq($(PROCESSOR), arm1176jz-s)\
NAME=ARM11.BIN
ifeq($(PROCESSOR), arm1176jzf-s)\
NAME=ARM11.BIN
#CREATE OBJECTS
ifeq($(CC), gcc)\
OBJECTS=$(FILES:.c=.o)
ifeq($(CC), g++)\
OBJECTS=$(FILES:.cpp=.o)
#FLAGS! DO NOT CHANGE THESE!!!!!!!!!!! THAT MEANS YOU!!!!!
#
#FOR THOSE WHO WANT TO KNOW WHAT THESE DO, HERE THEY ARE:
#-mtune=$(PROCESSOR) FORE THE COMPILER TO TUNE OUTPUT TO THE SPECIFIED
PROCESSOR
#-static REQUIRED FOR CLEAN BINARY OUTPUT?? (NOT SURE WHAT THIS
DOES, BUT WAS SUGESTED ON A POST ON STACKOVERFLOW)
#-fexceptions FORCE EXCEPTIONS
#-fnon-call-exceptions FORCE EXCEPTIONS TO ONLY BE RETURNED BY THE SYSTEM
(MEMORY AND FPU INSTRUTIONS FOR EXAMPLE)
#-fstack-check FORCE STACK CHECKING (DS / 3DS USE AWKWARD STACK
IMPLEMENTATION)
CFLAGS=-march=$(PROCESSOR) -static -fexceptions -fnon-call-exceptions -fstack-check
ALL:
$(CC) $(CFLAGS) $(FILES) -c
.c.o:
$(OBJC) $(OBJREFS) $(OBJECTS) $(NAME)
.cpp.o:
$(OBJC) $(OBJREFS) $(OBJECTS) $(NAME)
You are probably not calling the right gcc. You seem to be calling the gcc installed in your system, rather than the one that comes with the 3DS SDK.
It appears the problem is with -march=arm7tdmi.
I think the workaround is to avoid using -march=arm7tdmi; and use -march=cpu-type, where cpu-type is one of the ones listed at 3.17.4 ARM Options of the GCC manual.
Here's part of the page:
-march=name
This specifies the name of the target ARM architecture. GCC uses this name to determine what kind of instructions it can emit when
generating assembly code. This option can be used in conjunction with
or instead of the -mcpu= option. Permissible names are: ‘armv2’,
‘armv2a’, ‘armv3’, ‘armv3m’, ‘armv4’, ‘armv4t’, ‘armv5’, ‘armv5t’,
‘armv5e’, ‘armv5te’, ‘armv6’, ‘armv6j’, ‘armv6t2’, ‘armv6z’,
‘armv6kz’, ‘armv6-m’, ‘armv7’, ‘armv7-a’, ‘armv7-r’, ‘armv7-m’,
‘armv7e-m’, ‘armv7ve’, ‘armv8-a’, ‘armv8-a+crc’, ‘iwmmxt’, ‘iwmmxt2’,
‘ep9312’.

Good way to do a "switch" in a Makefile

I'm experimenting with an updated build system at work; currently, I'm trying to find a good way to set compiler & flags depending on the target platform.
What I would like to do is something like
switch $(PLATFORM)_$(BUILD_TYPE)
case "Linux_x86_release"
CFLAGS = -O3
case "Linux_x86_debug"
CFLAGS = -O0 -g
case "ARM_release"
CC = armcc
AR = armlink
CFLAGS = -O2 -fx
...
which is not supported by GNU Make. Now, my first thought was to just do
-include $(PLATFORM)_$(BUILD_TYPE)
which is a pretty decent solution, however, it makes it hard to get an overview of what differs between files, not to mention that I'm looking forward to writing & maintaining a good 60-80 files, each containing a set of variable definitions.
Does anyone happen to know a better way to accomplish this? I.e. setting a set of flags and other options based on another variable?
How about:
CFLAGS_Linux_x86_release = -O3
CFLAGS_Linux_x86_debug = -O0 -g
CFLAGS = ${CFLAGS_${PLATFORM}_${BUILD}}
Configuring such parameters would be the task of a configure script.
That being said, you can look into the syntax for conditionals and conditional functions. For example, you could try the following:
ifeq ($(PLATFORM)_$(BUILD_TYPE),Linux_x86_release)
CFLAGS = -O3
endif
ifeq ($(PLATFORM)_$(BUILD_TYPE),Linux_x86_debug)
CFLAGS = -O0 -g
endif
The Makefile used by git is a good example of a Makefile which does non-trivial configuration tasks in the Makefile itself (such as switching on the host type). It's actually quite readable and reasonably simple to use.
Switching to a system which does it for you (automake/autoconf) may be simpler...

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