There is already a build done, just create the directory PSP/GAMEP/picoloop.
Then unzip the last zip file from this thread in it and it will work.
But if you want to build a new psp binary here is what need to be check in this order :
1) you are able to compile an helloworld => EBOOT.BPB
2) you are able to compile an SDL helloworld => EBOOT.BPB
3) picoloop should build in this environment because you will use the same SDL and the same compiler, but I may have missed something.
First we will check your psp-g++ compiler.
You should have a working pspdev, and we need to validate it.
$ cd /tmp/
$ git clone https://github.com/yoyz/psp
$ cd /tmp/psp/starter
$ ls *
main.cpp Makefile psp_callback.cpp psp_callback.h
Now you have to source your environment variable to see the psp compiler.
In my case I have to launch this command ( I source a file which contain this variable ).
$ export PSPDEV=/home/yoyz/local/pspdev
$ export PATH=$PATH:$PSPDEV/bin
$ which psp-g++
/home/yoyz/local/pspdev/bin/psp-g++
Now you should be able to compile.
$ make
psp-g++ -I. -I/home/yoyz/local/pspdev/psp/sdk/include -G0 -Wall -O2 -I. -I/home/yoyz/local/pspdev/psp/sdk/include -G0 -Wall -O2 -fno-exceptions -fno-rtti -D_PSP_FW_VERSION=500 -c -o psp_callback.o psp_callback.cpp
psp-g++ -I. -I/home/yoyz/local/pspdev/psp/sdk/include -G0 -Wall -O2 -I. -I/home/yoyz/local/pspdev/psp/sdk/include -G0 -Wall -O2 -fno-exceptions -fno-rtti -D_PSP_FW_VERSION=500 -c -o main.o main.cpp
psp-gcc -I. -I/home/yoyz/local/pspdev/psp/sdk/include -G0 -Wall -O2 -D_PSP_FW_VERSION=500 -L. -L/home/yoyz/local/pspdev/psp/sdk/lib -specs=/home/yoyz/local/pspdev/psp/sdk/lib/prxspecs -Wl,-q,-T/home/yoyz/local/pspdev/psp/sdk/lib/linkfile.prx psp_callback.o main.o /home/yoyz/local/pspdev/psp/sdk/lib/prxexports.o -lGLU -lGL -ljpeg -lstdc++ -lm -lc -lpspvfpu -L/home/yoyz/local/pspdev/psp/lib -lSDLmain -lSDL -lm -lGL -lpspvfpu -L/home/yoyz/local/pspdev/psp/sdk/lib -L/home/yoyz/local/pspdev/psp -lpspdebug -lpspgu -lpspctrl -lpspge -lpspdisplay -lpsphprm -lpspsdk -lpsprtc -lpspaudio -lpsputility -lpspnet_inet -lpspirkeyb -lpsppower -lc -lpspuser -lSDL_ttf -lfreetype -lm -lpspdebug -lpspdisplay -lpspge -lpspctrl -lpspsdk -lc -lpspnet -lpspnet_inet -lpspnet_apctl -lpspnet_resolver -lpsputility -lpspuser -lpspkernel -o hello_world.elf
psp-fixup-imports hello_world.elf
psp-prxgen hello_world.elf hello_world.prx
mksfo 'Hello_World' PARAM.SFO
pack-pbp EBOOT.PBP PARAM.SFO NULL \
NULL NULL NULL \
NULL hello_world.prx NULL
[0] 408 bytes | PARAM.SFO
[1] 0 bytes | NULL
[2] 0 bytes | NULL
[3] 0 bytes | NULL
[4] 0 bytes | NULL
[5] 0 bytes | NULL
[6] 91290 bytes | hello_world.prx
[7] 0 bytes | NULL
If this is okay then your toolchain is able to compile a EBOOT.BPB file.
Tell me if it is okay and we will add some SDL stuff in the helloworld.