boot2

Playing with the boostrap
git clone https://git.ryansepassi.com/git/boot2.git
Log | Files | Refs | README

entry-libc.P1pp (895B)

      1 # P1/entry-libc.P1pp — executable entry stub for links that include
      2 # our libc (vendor/mes-libc + boot2-syscall.c).
      3 #
      4 # Same shape as entry-plain.P1pp but threads __libc_init in front of
      5 # main. __libc_init (boot2-syscall.c) reads argv's NULL terminator
      6 # to populate `environ` so getenv()/etc don't dereference a NULL
      7 # environment pointer on the first call. argc/argv arrive in a0/a1
      8 # from the bootstrap _start; save them across __libc_init so main sees
      9 # the original process arguments even if libc init returns through a0.
     10 #
     11 # Cat this in exactly once at the head of a libc-using catm chain
     12 # and pair with P1/elf-end.P1pp at the tail. Library TUs (libc,
     13 # client) should be built with cc.scm --lib=PFX so they don't
     14 # also try to define :p1_main.
     15 
     16 %fn(p1_main, 16, {
     17     %st(a0, sp, 0)
     18     %st(a1, sp, 8)
     19     %call(&__libc_init)
     20     %ld(a0, sp, 0)
     21     %ld(a1, sp, 8)
     22     %call(&main)
     23 })