[Wisp-cvs] wisp/users/dig elf.py,1.11,1.12 makehello.py,1.10,1.11
Status: Alpha
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[Wisp-cvs] wisp/users/dig elf.py,1.11,1.12 makehello.py,1.10,1.11
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From: <di...@us...> - 2003-02-17 20:27:23
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Update of /cvsroot/wisp/wisp/users/dig
In directory sc8-pr-cvs1:/tmp/cvs-serv22412
Modified Files:
elf.py makehello.py
Log Message:
first ELF32 executable with symbols (static linkage, no relocation) generated
Index: elf.py
===================================================================
RCS file: /cvsroot/wisp/wisp/users/dig/elf.py,v
retrieving revision 1.11
retrieving revision 1.12
diff -u -d -r1.11 -r1.12
--- elf.py 16 Feb 2003 10:48:17 -0000 1.11
+++ elf.py 17 Feb 2003 20:27:18 -0000 1.12
@@ -370,7 +370,7 @@
t.align(4)
t.emit_string('\0' * 40) # the null entry
for name in names:
- t.emit_tetra_sum(['.shstr/strings/' + name])
+ t.emit_tetra_sum(['.shstrtab/strings/' + name])
t.emit_tetra_sum([name + '/sh_type'])
t.emit_tetra_sum([name + '/sh_flags'])
t.emit_tetra_sum([name])
Index: makehello.py
===================================================================
RCS file: /cvsroot/wisp/wisp/users/dig/makehello.py,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -d -r1.10 -r1.11
--- makehello.py 17 Feb 2003 00:19:08 -0000 1.10
+++ makehello.py 17 Feb 2003 20:27:18 -0000 1.11
@@ -18,6 +18,8 @@
m.place_symbol(name)
return m
+sections = {}
+
code = Linkie('<') # ia32
code.place_symbol('_start')
code.emit_byte(0xBA); code.emit_tetra(14) # mov edx, 14
@@ -29,9 +31,11 @@
code.emit_byte(0xB8); code.emit_tetra(1) # mov eax, 1
code.emit_byte(0xCD); code.emit_byte(0x80) # int 0x80
-data = Linkie('<') # ia32
-data.place_symbol('message')
-data.emit_string('Hello, world!\n')
+sections['.text'] = code; del code
+
+sections['.data'] = Linkie('<') # ia32
+sections['.data'].place_symbol('message')
+sections['.data'].emit_string('Hello, world!\n')
def infer_by_prefix (name, dict):
for l in range(len(name), -1, -1):
@@ -42,26 +46,32 @@
def guess_shtype (name):
return infer_by_prefix(name, {'': SHT.PROGBITS,
'.bss': SHT.NOBITS,
+ '.dynstr': SHT.STRTAB,
'.note': SHT.NOTE,
- '.shstr': SHT.STRTAB})
+ '.shstrtab': SHT.STRTAB,
+ '.symstr': SHT.STRTAB,
+ '.symtab': SHT.SYMTAB,
+ })
def guess_ptype (name):
return infer_by_prefix(name, {'': PT.LOAD,
'.note': PT.NOTE})
def guess_flags (name):
- return infer_by_prefix(name, {'': 'rw--',
- '.bss': 'rw--',
- '.comment': '----',
- '.data': 'rw--',
- '.debug': '----',
- '.line': '----',
- '.note': '----',
- '.rodata': 'r---',
- '.shstr': '---s',
- '.text': 'r-x-'})
+ return infer_by_prefix(name, {'': 'rw--',
+ '.bss': 'rw--',
+ '.comment': '----',
+ '.data': 'rw--',
+ '.debug': '----',
+ '.dynstr': 'a--s',
+ '.line': '----',
+ '.note': '----',
+ '.rodata': 'r---',
+ '.shstrtab': '---s',
+ '.symstr': 'a--s',
+ '.text': 'r-x-'})
def guess_shflags (name):
flags = guess_flags(name)
sh_flags = 0
- if 'r' in flags: sh_flags |= SHF.ALLOC
+ if 'r' in flags or 'a' in flags: sh_flags |= SHF.ALLOC
if 'w' in flags: sh_flags |= SHF.ALLOC | SHF.WRITE
if 'x' in flags: sh_flags |= SHF.ALLOC | SHF.EXECINSTR
if 's' in flags: sh_flags |= SHF.STRINGS
@@ -76,26 +86,39 @@
symbols = {}
-shstr = Linkie('<')
-shstr.emit_byte(0)
-symbols['.shstr/strings/.text'] = shstr.filesz()
-shstr.emit_string('.text\0')
-symbols['.shstr/strings/.data'] = shstr.filesz()
-shstr.emit_string('.data\0')
-symbols['.shstr/strings/.shstr'] = shstr.filesz()
-shstr.emit_string('.shstr\0')
-
hello = Linkie('<')
memory_boundary = 0x8048000 # must be at page boundary
hello.extend(make_ELF32_header('<'))
symbols['elf/type'] = ET.EXEC
symbols['elf/machine'] = EM.I386
symbols['elf/flags'] = 0 # no flags for ia386
-program_header_table = make_ELF32_phtable('<', ['.text', '.data'])
+
+shentnames = ['.text', '.data', '.symstr', '.symtab', '.shstrtab']
+
+sections['.shstrtab'] = Linkie('<')
+sections['.shstrtab'].emit_byte(0)
+
+sections['.symstr'] = Linkie('<')
+sections['.symstr'].emit_byte(0)
+
+sections['.symtab'] = Linkie('<')
+sections['.symtab'].align(4)
+sections['.symtab'].emit_string('\0' * 16)
+
+phentnames = []
+for name in shentnames:
+ if guess_pflags(name) <> 0:
+ phentnames.append(name)
+ symbols['.shstrtab/strings/' + name] = sections['.shstrtab'].filesz()
+ sections['.shstrtab'].emit_string(name)
+ sections['.shstrtab'].emit_byte(0)
+
+program_header_table = make_ELF32_phtable('<', phentnames)
symbols['elf/phoff'] = hello.extend(program_header_table)
-symbols['elf/phnum'] = 2
+symbols['elf/phnum'] = len(phentnames)
-for name, section in (('.text', code), ('.data', data), ('.shstr', shstr)):
+for name in shentnames:
+ section = sections[name]
p_flags = guess_pflags(name)
alignment = section.get_alignment()
symbols[name + '/sh_align'] = alignment
@@ -136,19 +159,30 @@
if address <> None:
for symbol, value in section.get_symbols():
symbols[symbol] = address + value
- print '%s = %08x' % (symbol, address + value)
for symbol, value in section.get_symbols():
hello.place_symbol(symbol, offset + value) # for dump to work nicely
+ sofs = sections['.symstr'].filesz()
+ symbols['.symstr/strings/' + symbol] = sofs
+ sections['.symstr'].emit_string(symbol)
+ sections['.symstr'].emit_byte(0)
+ sections['.symtab'].emit_tetra(sofs)
+ sections['.symtab'].emit_tetra_sum([name])
+ sections['.symtab'].emit_tetra(0)
+ sections['.symtab'].emit_byte(STB.GLOBAL << 4 | STT.NOTYPE)
+ sections['.symtab'].emit_byte(0)
+ sections['.symtab'].emit_wyde(shentnames.index(name) + 1)
+
for loc, typ, arg in section.get_notes():
hello.notify_linker(offset + loc, typ, arg)
memory_boundary += section.memsz()
memory_boundary = (memory_boundary + 0xFFF) & ~0xFFF
# create section header table
-section_header_table = make_ELF32_shtable('<', ['.text', '.data', '.shstr'])
+section_header_table = make_ELF32_shtable('<', shentnames)
symbols['elf/shoff'] = hello.extend(section_header_table)
-symbols['elf/shnum'] = 4
-symbols['elf/shstrndx'] = 3
+symbols['elf/shnum'] = len(shentnames) + 1
+symbols['elf/shstrndx'] = shentnames.index('.shstrtab') + 1
+symbols['.symtab/sh_link'] = shentnames.index('.symstr') + 1
hello.link(symbols)
hello.dump()
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