Hello all, I've a problem with nano-X (CVS sources) and GrLoadImageFromFile for PNG type image only with the cross-compiled version of nano-X on my target (arm - CPU PXA270) but not with the nano-X binary running on my host (x86) : I investigate the problem (following step of investigations) and found the line code that generate a SEGFAULT in nano-X in this situation :
1/ To support PNG I've build the libpng (version 1.2.38 sources from http://www.libpng.org) and zlib (version 1.2.3 sources from http://www.zlib.org) for my target architecture (with arm-linux-gnueabi tool chain), install them in the cross-chain location, and rebuild nano-X with same cross-chain and use this previous libs. some config of nano-X are : ARCH = LINUX-ARM HAVE_PNG_SUPPORT = Y INCPNG = /usr/local/arm-linux/arm-linux/include/ LIBPNG = /usr/local/arm/oe/arm-linux-gnueabi/lib/libpng.a INCZ = /usr/local/arm-linux/arm-linux/include/ LIBZ = /usr/local/arm/oe/arm-linux-gnueabi/lib/libz.a Everything compiled with success (nano-X + demos) and copy into the target. 2/ On the target when I run ./nano-X & ./nxview image.png , nano-X crash with a Segmentation fault. Note that running ./nano-X & ./nvxiew image.png on my host (x86) (with nano-X and demos compiled for x86 architecture) work perfectly ! 3/ I've rebuild nano-X and demos with DEBUG=Y and OPTFLAGS += -ggdb -O0 to be able to run nano-X with gdbserver on the target and watch with gdb exactly the problem After this step (and some long time to compil and crosscompil gdb/gdbserver ;)) I check the followings : Program received signal SIGSEGV, Segmentation fault. 0x00017f6c in GdImageBufferRead (buffer=0x0, dest=0xbe82a4f4, size=8) at /home/vincent/microwindows-cvs/src/engine/devimage.c:78 In fact, a NULL pointer for buffer for the call of int GdImageBufferRead(buffer_t *buffer, void *dest, unsigned long size) (in devimage.c) called by the png_read_buffer function (in image_png.c), and the first line of GdImageBufferRead that is buffer->offset generate a SEGFAULT With add of if (buffer==0 || dest==0) return -1; at the begenning of the GdImageBufferRead function and same procedure, nano-X doesn't crash, nvxiew display 'Can't load image file' and both terminate normaly. 4/ Continuing my investigations with step by step on ddd (on host side) and gdbserver (on target side) I notice that in GdDecodePNG (image_png.c) png_structp state always contain 0 for all fields BUT during step execution of png_init_io(state, src); (into this function, into the lib) the contents of the structure seems to be good, but not after leaving and return in the GdDecodePNG function. (strange) I note that when compiling nano-X I've got this warning: passing argument 2 of 'png_init_io' from incompatible pointer type. Argument 2 if the src pointer (buffer_t *) and png_init_io require a png_FILE_p type, but even when casting (png_FILE_p)src for the png_init_io call (no more warning) but same result... Now I can't continue some investigations and require some helps... Does anybody try and reach to cross compil nano-X with libpng for arm architecture and display some PNG image with ?? Is there's some particular options for the libpng or/and zlib build to work with nano-X ? Sorry for this long mail but need to be clear. Can anybody help me please ? Regards, Vincent BRACH
