Found Chromium is using a shell script that calls od and sed. https://chromium.googlesource.com/chromiumos/platform/ec/+/m...
Embedding Binary Objects in C
31–40 of 141 posts
Re: Embedding Binary Objects in C
#32Back in the day Borland shipped a tool called binobj which did exactly this.
Re: Embedding Binary Objects in C
#33C++ has a proposal for std::embed http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p104...
C has a proposal for #embed.
Re: Embedding Binary Objects in C
#34My favorite is simply using a tool to create a C file with your binary data: static uint8_t mydata[] = {0xDE, 0xAD, 0xBE, 0xEF, ... }; The advantage is that it works anywhere, with any compiler. The disadvantage is that it can increase compile time. I would limit each .c file to 10MB; it seems there's a quadratic increase in build time with file size, at least with gcc. Also, instead of "0x%02x" I use decimal notatio…
nice salu2
Re: Embedding Binary Objects in C
#35I wouldn't do it this way, within the toolchain. Better to just append the data to the finished executable, with a header that contains an identifying marker. The program can scan its own image and look for that marker to get at the data. That will work on any OS with any executable and linker format and can be done post-production (users or downstream distributors can receive the binary and add customized data to it without requiring a dev environment with a toolchain, just tiny utility you can bundle with the program).
Scanning for the marker can be avoided, if we do the following:
/* inside the program, at file scope */
struct {
char marker[16] = "dW5pcXVlbWFyawo="
uint32 offset;
} binary_stuff;
When the program runs, if it sees a nonzero value in binary_stuff.offset, it can open its image and directly proceed to that offset to read the stuff or map it: no searching.
Re: Embedding Binary Objects in C
#36If we're in the realm of "non-standard linker tricks"... Compilers will concatenate sections of the same name. You can use this trick to produce a concatenation of arrays across several files: $ cat t1.c __attribute__((section("some_array"))) int a[] = {1, 2, 3}; $ cat t2.c __attribute__((section("some_array"))) int b[] = {4, 5, 6}; $ cat t.c #include extern const int __start_some_array; extern const int __stop_some_…
How exactly is the ordering of items across the section decided? Is it relatively random or is it based on the order that the object files are passed to the linker?
Re: Embedding Binary Objects in C
#37I needed this last week! Building an embedded firmware image for a dashboard display, with lots of PNG files for icons etc. 61 of them. The original developer wrote a tool to expand the PNGs to BMPs (arrays of 32-bit pixel values) and generate a C array definition as a text file. Which is lots bigger than the original PNG (13K => 100K sort of thing). Then included that C source in the build. Used up 700K of my firmwa…
Nope. Dumb Visual Studio doesn't support embedded binary in cross-compile. That's the tool the client wanted, so I'm stuck with it.
Funny, they (VisualGDB) even have a tutorial on doing it. But the option 'Embedded Resource' doesn't exist in my (modern) Visual Studio.
Ha! And the feedback I gave VisualGDB about their outdated tutorial, they responded "Just pay HERE and we'll be glad to solve your problem!" They can go ahead and have outdated documentation, screw them.
Re: Embedding Binary Objects in C
#38I needed this last week! Building an embedded firmware image for a dashboard display, with lots of PNG files for icons etc. 61 of them. The original developer wrote a tool to expand the PNGs to BMPs (arrays of 32-bit pixel values) and generate a C array definition as a text file. Which is lots bigger than the original PNG (13K => 100K sort of thing). Then included that C source in the build. Used up 700K of my firmwa…
There are even smaller png libs than libpng, try a stripped down stb_image for example. Wouldn't use that for user-supplied images, but since you control them all it should be fine.
Re: Embedding Binary Objects in C
#39I wouldn't do it this way, within the toolchain. Better to just append the data to the finished executable, with a header that contains an identifying marker. The program can scan its own image and look for that marker to get at the data. That will work on any OS with any executable and linker format and can be done post-production (users or downstream distributors can receive the binary and add customized data to it…
Sounds like a great vector for malware.
Re: Embedding Binary Objects in C
#40I wouldn't do it this way, within the toolchain. Better to just append the data to the finished executable, with a header that contains an identifying marker. The program can scan its own image and look for that marker to get at the data. That will work on any OS with any executable and linker format and can be done post-production (users or downstream distributors can receive the binary and add customized data to it…
The advantage of the approach described in the article is that there's less work to do at startup time. For applications that run on end-users' machines, we should do whatever we can to minimze work done at startup, getting it as close as possible to just mapping a big blob into memory and jumping to the code that does the real work of the program.