Building Cross-Compiler: Intel Xeon E5649 >>> ARMv7 with libcURL - c

Question

i don't exactly understand the manual/help from libcURL. I'm trying to build a Cross-Compiler including the libcURL library. I installed a Cross-Compiler on my Server with the help of this video and can start it with arm-linux-gnueabihf-gcc hello_simple.c. I could compile simple c-code like printf ("Hello World"); After that i tried to install libcURL and read that I need to compile the lib and use the configure file to set the build and host. I used different configuration like: sudo ./configure --build=i586-pc-linux-gnu --host=arm-linux --target=arm-linux --prefix=/home/nevadmin/dev/gcc but neither did one worked. I think I'm making somewhere mistakes. This is the output after configuration is made:
curl version: 7.46.0
Host setup: arm-unknown-linux-gnu
Install prefix: /home/nevadmin/dev/gcc
Compiler: gcc
SSL support: no (--with-{ssl,gnutls,nss,polarssl,mbedtls,cyassl,axtls,winssl,darwinssl} )
SSH support: no (--with-libssh2)
zlib support: no (--with-zlib)
GSS-API support: no (--with-gssapi)
TLS-SRP support: no (--enable-tls-srp)
resolver: default (--enable-ares / --enable-threaded-resolver)
IPv6 support: no (--enable-ipv6)
Unix sockets support: enabled
IDN support: no (--with-{libidn,winidn})
Build libcurl: Shared=yes, Static=yes
Built-in manual: enabled
--libcurl option: enabled (--disable-libcurl-option)
Verbose errors: enabled (--disable-verbose)
SSPI support: no (--enable-sspi)
ca cert bundle: no
ca cert path: no
LDAP support: no (--enable-ldap / --with-ldap-lib / --with-lber-lib)
LDAPS support: no (--enable-ldaps)
RTSP support: enabled
RTMP support: no (--with-librtmp)
metalink support: no (--with-libmetalink)
PSL support: no (libpsl not found)
HTTP2 support: disabled (--with-nghttp2)
Protocols: DICT FILE FTP GOPHER HTTP IMAP POP3 RTSP SMTP TELNET TFTP
My Server cpuinfo:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 44
model name : Intel(R) Xeon(R) CPU E5649 # 2.53GHz
stepping : 2
microcode : 0x15
cpu MHz : 2533.423
cache size : 12288 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 popcnt aes hypervisor lahf_lm ida arat dtherm
bogomips : 5066.84
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:
And my controller:
Processor : ARMv7 Processor rev 2 (v7l)
BogoMIPS : 298.80
Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x3
CPU part : 0xc08
CPU revision : 2
Using for example gcc hello_world.c -o hello_world it compile it for the amd processor architecture and not arm. It seems I'm missing the linking to the library for libcURL? I appreciate every help. And sorry my english, it's not my native language.
Linking with L/home/nevadmin/dev/gcc -lcurl is working an I can compile a c-code with libcURL but it still compiling it for amd64 and not arm. :/

Answer 1

You need to set the proper compiler to use when you configure curl. If you look at curl's configure output from
./configure --help
You'll see this at the end:
...
Some influential environment variables:
CC C compiler command
CFLAGS C compiler flags
LDFLAGS linker flags, e.g. -L<lib dir> if you have libraries in a
nonstandard directory <lib dir>
LIBS libraries to pass to the linker, e.g. -l<library>
CPPFLAGS (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
you have headers in a nonstandard directory <include dir>
CPP C preprocessor
Use these variables to override the choices made by `configure' or to help
it to find libraries and programs with nonstandard names/locations.
You can set these variables with a command line like:
CC=arm-linux-gnueabihf-gcc ./configure --build=i586-pc-linux-gnu --host=arm-linux --target=arm-linux --prefix=/home/nevadmin/dev/gcc
(You don't need the "sudo" to configure.)
gcc by itself will give you an AMD executable. You need to use arm-linux-gnueabihf-gcc to get an ARM executable.
Notice that in your curl configuration output it says
Compiler: gcc
That's why your getting a curl library built for your AMD. Bibliothek is called "library" in English. ;-)
If you continue to have problems cross compiling for ARM you could take a look at the binary releases of the cross compilation tool chain ELLCC. As of version 0.1.21 it comes with several pre-compiled libraries, including curl. Here's the ChangeLog.