diff --git a/Embedding-binary-data-in-your-psx-executable.md b/Embedding-binary-data-in-your-psx-executable.md new file mode 100644 index 0000000..690bb11 --- /dev/null +++ b/Embedding-binary-data-in-your-psx-executable.md @@ -0,0 +1,55 @@ +## Embedding binary data in a ps-exe + +So, if you don't know it yet, the fun in PSX development is to be able to upload your exes on real hardware with a USB/Serial cable. +This means that the data you'll use in your program ( graphics, sounds, etc.) will have to be embedded in your exe in a binary form, +as you won't be able to stream them from the serial port. + +*Well technically you could load them in memory before uploading your exe or stream them from a cd, but let's keep things simple for now.* + +With our setup, this is quite easy ! + + 1. In `common.mk` , add the lines : + + ```mk +# convert TIM file to bin +%.o: %.tim + $(PREFIX)-objcopy -I binary --set-section-alignment .data=4 --rename-section .data=.rodata,alloc,load,readonly,data,contents -O elf32-tradlittlemips -B mips $< $@ + +# convert VAG files to bin +%.o: %.vag + $(PREFIX)-objcopy -I binary --set-section-alignment .data=4 --rename-section .data=.rodata,alloc,load,readonly,data,contents -O elf32-tradlittlemips -B mips $< $@ +``` + +If you pay attention, you can see that's the same command, but for different file types. TIM files are bitmap images and VAG is the sound format used in this example. +Each time you'll want to add a file type, duplicate and change `%.vag` to `%.filetype` + +Then, in your project folder, copy the makefile from the cube example : + +```bash +mkdir new_project && cd new_project +cp ../cube/Makefile ../ +``` + +All you have to do now is add the files you wish to embed to the SRCS variable, without forgetting the \ : + +```bash +SRCS = main.c \ +../common/crt0/crt0.s \ +file_to_embed.ext \ +``` + + 2. So this part takes care of converting our data to binary. Now to access them from your program, use this in your sources : +```c +extern ulong _binary_filename_extension_start[]; +extern ulong _binary_filename_extension_end[]; +extern ulong _binary_bowsht_tim_length[]; +``` + +The filename variable must begin with `_binary_` followed by the full path of your file, with . and / replaced by _ (underscore), and end with `_start[];` or `_end[];` or `_length[];` [source](https://discord.com/channels/642647820683444236/663664210525290507/780866265077383189) + +`_start` and `_end` are pointers, while `_length` is a constant. + +If you want to go up one level in the folder hierarchy, you can use four underscores : `____`. +This is because `/../` are characters that will be replaced with `_`. + +That's it! When you'll type `make` next time, it should convert your files to .o, then include them in your ps-exe.