Merge pull request #93 from Daft-Freak/reloc-itcm

Fixes to reloc tool for ITCM

src/tests/test_relocs.py

@@ -19,6 +19,22 @@ def test_input_elf(test_resources):
     return temp_bin
 
 
+@pytest.fixture
+def test_input_bin_itcm(test_resources):
+    temp_bin = tempfile.NamedTemporaryFile('r+b', suffix='.bin')
+    temp_bin.write(open(test_resources / "itcm-test.bin", "rb").read())
+    temp_bin.flush()
+    return temp_bin
+
+
+@pytest.fixture
+def test_input_elf_itcm(test_resources):
+    temp_bin = tempfile.NamedTemporaryFile('r+b', suffix='.bin')
+    temp_bin.write(open(test_resources / "itcm-test.elf", "rb").read())
+    temp_bin.flush()
+    return temp_bin
+
+
 @pytest.fixture
 def test_output_file():
     temp_bin = tempfile.NamedTemporaryFile('r+b', suffix='.blit')
@@ -35,3 +51,14 @@ def test_relocs(test_input_bin, test_input_elf, test_output_file):
             '--elf-file', test_input_elf.name,
             '--output', test_output_file.name
         ])
+
+def test_relocs_itcm(test_input_bin_itcm, test_input_elf_itcm, test_output_file):
+    from ttblit import main
+
+    with pytest.raises(SystemExit):
+        main([
+            'relocs',
+            '--bin-file', test_input_bin_itcm.name,
+            '--elf-file', test_input_elf_itcm.name,
+            '--output', test_output_file.name
+        ])

src/ttblit/tool/relocs.py

@@ -26,6 +26,10 @@ def relocs_cli(bin_file, elf_file, output):
         # find sidata/sdata
         sidata = 0
         sdata = 0
+
+        itcm_data = 0
+        itcm_text_start = 0
+
         relocs = elffile.get_section_by_name('.rel.text')
         symtable = elffile.get_section(relocs['sh_link'])
         for reloc in relocs.iter_relocations():
@@ -34,8 +38,12 @@ def relocs_cli(bin_file, elf_file, output):
                 sidata = symbol['st_value']
             elif symbol.name == '_sdata':
                 sdata = symbol['st_value']
+            elif symbol.name == 'itcm_data':
+                itcm_data = symbol['st_value']
+            elif symbol.name == 'itcm_text_start':
+                itcm_text_start = symbol['st_value']
 
-            if sidata and sdata:
+            if sidata and sdata and itcm_data and itcm_text_start:
                 break
 
         assert(sidata != 0 and sdata != 0)
@@ -61,6 +69,52 @@ def relocs_cli(bin_file, elf_file, output):
 
             reloc_offsets.append(flash_offset)
 
+        # references to the GOT from ITCM code
+        relocs = elffile.get_section_by_name('.rel.itcm')
+        if relocs:
+            symtable = elffile.get_section(relocs['sh_link'])
+
+            for reloc in relocs.iter_relocations():
+                symbol = symtable.get_symbol(reloc['r_info_sym'])
+
+                # doesn't point to flash
+                if symbol['st_value'] < 0x90000000:
+                    continue
+
+                if symbol.name == '_GLOBAL_OFFSET_TABLE_':
+                    flash_offset = (reloc['r_offset'] - itcm_text_start) + itcm_data
+
+                    reloc_offsets.append(flash_offset)
+
+        # fixup ITCM veneers for long calls back to flash
+        itcm_section = elffile.get_section_by_name('.itcm')
+        if itcm_section:
+            itcm_section_data = itcm_section.data()
+
+            for i in range(symtable.num_symbols()):
+                sym = symtable.get_symbol(i)
+
+                if sym.name.endswith('_veneer') and sym['st_value'] < 0xF800:
+                    # find where the target function is (strip leading __ and trailing _veneer from name)
+                    orig_sym = symtable.get_symbol_by_name(sym.name[2:-7])[0]
+                    target_addr = orig_sym['st_value']
+
+                    # make sure it's in flash
+                    if target_addr < 0x90000000:
+                        continue
+
+                    # find the function in flash
+                    itcm_offset = (sym['st_value'] - itcm_text_start) & ~1 # clear thumb bit
+                    flash_offset = itcm_offset + itcm_data
+
+                    # check for the address where we expect it
+                    # (ldr.w pc, [pc] followed by the address)
+                    ex_addr, = struct.unpack('<I', itcm_section_data[itcm_offset + 4:itcm_offset + 8])
+
+                    assert ex_addr == target_addr
+
+                    reloc_offsets.append(flash_offset + 4)
+
         with open(output, 'wb') as out_f:
             all_offsets = got_offsets + init_offsets + fini_offsets + reloc_offsets
             all_offsets.sort()