src->rt; smol*.py -> src; add optional 16-bit hash version

.gitignore

 /bin
 /obj
-/__pycache__
+__pycache__

Makefile

 OBJDIR := obj
 BINDIR := bin
-SRCDIR := src
+SRCDIR := rt
+PYDIR  := src
 LDDIR  := ld
 TESTDIR:= test
 
@@ -40,7 +41,7 @@ CXXFLAGS += -m$(BITS) $(shell pkg-config --cflags sdl2)
 
 LIBS=-lc
 
-SMOLFLAGS +=
+SMOLFLAGS += -s
 ASFLAGS   += -DUSE_INTERP -DUSE_DNLOAD_LOADER -DNO_START_ARG -DUNSAFE_DYNAMIC #-DALIGN_STACK
 #-DUSE_DNLOAD_LOADER #-DUSE_DT_DEBUG #-DUSE_DL_FINI #-DNO_START_ARG #-DUNSAFE_DYNAMIC
 
@@ -73,7 +74,7 @@ $(OBJDIR)/%.start.o: $(OBJDIR)/%.lto.o $(OBJDIR)/crt1.lto.o
 	$(CC) $(LDFLAGS) -r -o "$@" $^
 
 $(OBJDIR)/symbols.%.asm: $(OBJDIR)/%.o
-	$(PYTHON3) ./smol.py $(SMOLFLAGS) $(LIBS) "$<" "$@"
+	$(PYTHON3) $(PYDIR)/smol.py $(SMOLFLAGS) $(LIBS) "$<" "$@"
 
 $(OBJDIR)/stub.%.o: $(OBJDIR)/symbols.%.asm $(SRCDIR)/header32.asm \
         $(SRCDIR)/loader32.asm

src/loader32.asm → rt/loader32.asm

@@ -11,7 +11,7 @@
 
 
 _smol_start:
-
+;.loopme: jmp short .loopme
 %ifdef USE_DL_FINI
    push edx ; _dl_fini
 %endif
@@ -81,28 +81,46 @@ _smol_start:
             add esi, ebx
 
            push ecx
+%ifndef USE_HASH16
            push ebx
            push 33
            push 5381
             pop eax
             pop ebx
+%else
+            xor eax, eax
+%endif
             xor ecx, ecx
         .nexthashiter:
-            xchg eax, ecx
-           lodsb
-              or al, al
-            xchg eax, ecx
-              jz short .breakhash
-
-            push edx
-             mul ebx
-             pop edx
-             add eax, ecx
-             jmp short .nexthashiter
+                    ;
+               xchg eax, ecx
+              lodsb
+                 or al, al
+               xchg eax, ecx
+                 jz short .breakhash
+
+%ifndef USE_HASH16
+               push edx
+                mul ebx
+                pop edx
+;               add eax, ecx
+%else
+                ror ax, 2
+;               add ax, cx
+%endif
+                add eax, ecx
+                jmp short .nexthashiter
 
         .breakhash:
+%ifndef USE_HASH16
             pop ebx
+%endif
             pop ecx
+;%ifndef USE_HASH16
+;           cmp ecx, eax
+;%else
+;           cmp  cx,  ax
+;%endif
             cmp ecx, eax
              je short .hasheq
 
@@ -244,7 +262,7 @@ link.done:
 %ifdef USE_DL_FINI
        pop edx      ; _dl_fini
 %endif
-           ; move esp into eax, *then* increase the stack by 4, as main() 
+           ; move esp into eax, *then* increase the stack by 4, as main()
            ; expects a return address to be inserted by a call instruction
            ; (which we don't have, so we're doing a 1-byte fixup instead of a
            ; 5-byte call)

smol.py → src/smol.py

@@ -30,6 +30,9 @@ def main():
     parser.add_argument('--readelf', default=shutil.which('readelf'), \
         help="which readelf binary to use")
 
+    parser.add_argument('-s', '--hash16', default=False, action='store_true', \
+        help="Use 16-bit (BSD) hashes instead of 32-bit djb2 hashes. "\
+            +"Conflicts with -DUSE_DNLOAD_LOADER")
 #   parser.add_argument('-d', '--dnload', default=False, action='store_true', \
 #       help="Use dnload's mechanism of importing functions. Slightly larger, but usually better compressable.")
 #   parser.add_argument('--libsep', default=False, action='store_true', \
@@ -69,7 +72,7 @@ def main():
         symbols.setdefault(library, [])
         symbols[library].append((symbol, reloc))
 
-    output(arch, symbols, args.nx, args.output)
+    output(arch, symbols, args.nx, args.hash16, args.output)
 
 if __name__ == '__main__':
     main()

smolemit.py → src/smolemit.py

@@ -3,11 +3,11 @@ import sys
 
 from smolshared import *
 
-def output_x86(libraries, nx, outf):
+def output_x86(libraries, nx, h16, outf):
     outf.write('; vim: set ft=nasm:\n') # be friendly
 
-    if nx:
-        outf.write('%define USE_NX 1\n')
+    if nx:  outf.write('%define USE_NX 1\n')
+    if h16: outf.write('%define USE_HASH16 1\n')
 
     usedrelocs = set({})
     for library, symrels in libraries.items():
@@ -56,7 +56,7 @@ dynamic.end:
                 eprintf('Relocation type ' + reloc + ' of symbol ' + sym + ' unsupported!')
                 sys.exit(1)
 
-            hash = hash_djb2(sym)
+            hash = hash_bsd2(sym) if h16 else hash_djb2(sym)
             if nx:
                 outf.write("\t\t_symbols.{lib}.{name}: dd 0x{hash:x}"\
                     .format(lib=shorts[library],name=sym,hash=hash).lstrip('\n'))
@@ -87,7 +87,14 @@ global {name}
 # end output_x86
 
 
-def output_amd64(libraries, outf):
+def output_amd64(libraries, nx, h16, outf):
+    if h16:
+        eprintf("--hash16 not supported yet for x86_64 outputs.")
+        exit(1)
+
+    if nx:  outf.write('%define USE_NX 1\n')
+#   if h16: outf.write('%define USE_HASH16 1\n')
+
     outf.write('; vim: set ft=nasm:\n')
     outf.write('bits 64\n')
 
@@ -129,7 +136,7 @@ global {name}
 {name}:
 """.format(name=sym).lstrip('\n'))
 
-            hash = hash_djb2(sym)
+            hash = hash_bsd2(sym) if h16 else hash_djb2(sym)
             outf.write('\t\t_symbols.{lib}.{name}: dq 0x{hash:x}\n'\
                        .format(lib=shorts[library],name=sym,hash=hash))
 
@@ -152,9 +159,9 @@ global {name}
 # end output_amd64
 
 
-def output(arch, libraries, nx, outf):
-    if arch == 'i386': output_x86(libraries, nx, outf)
-    elif arch == 'x86_64': output_amd64(libraries, outf)
+def output(arch, libraries, nx, h16, outf):
+    if arch == 'i386': output_x86(libraries, nx, h16, outf)
+    elif arch == 'x86_64': output_amd64(libraries, nx, h16, outf)
     else:
         eprintf("E: cannot emit for arch '" + str(arch) + "'")
         sys.exit(1)

smolshared.py → src/smolshared.py

@@ -3,9 +3,16 @@ import sys
 
 archmagic = {
     'i386':    3,  3: 'i386'  ,
+   # arm: 40
     'x86_64': 62, 62: 'x86_64',
 }
 
+def hash_bsd2(s):
+    h = 0
+    for c in s:
+        h = ((h >> 2) + ((h & 3) << 14) + ord(c)) & 0xFFFF
+    return h
+
 def hash_djb2(s):
     h = 5381
     for c in s: