bss should be cleared with zeros when loading a program about baremetal-os-legacy

[dsriram]

Since we are using a flat binary format it would be almost impossible to know the offset for the bss segment, unless we switch over to ELF.

[IanSeyler]

Even at compile time? ELF could be a possibility down the line.

[dsriram]

How about this compile time structure for the .app header?

struc OS_APP_HEADER

  .flags_addr:        resq    1
  .code_addr:        resq    1 
  .data_addr:        resq    1
  .bss_addr:         resq    1

endstruc

this is just a nasm struc representation. the actual table will be generated through the linker script at compile time

[IanSeyler]

Linking the application with crt0.o fixes this issue. This will be added to the Newlib / C instructions.

ld -T app.ld -o helloc.app crt0.o helloc.o libc.a