1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
#!/usr/bin/env python3
"""
Find GSP firmware functions using the actual calling convention:
- Prologue: addi sp, sp, -N; sd s1-s11, offsets(sp); addi s0, sp, N
- ra saved to callee-saved reg: mv sX, ra (or c.mv sX, ra)
- Epilogue: mv ra, sX (or c.mv ra, sX); ret
"""
import struct
import json
import os
FWIMAGE_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), "gsp-570.144.fwimage.bin")
OUTPUT_DIR = os.path.dirname(os.path.abspath(__file__))
BASE_ADDR = 0x04000000
# Executable sections
EXEC_SECTIONS = [
(0x04005000, 0x04006413),
(0x04007000, 0x04008413),
(0x04009000, 0x04009073),
(0x0400a000, 0x0400cfff),
(0x0400e000, 0x04010fff),
(0x04018000, 0x0401cfff),
(0x04c58000, 0x05b21fff),
]
def read_binary(path):
with open(path, 'rb') as f:
return f.read()
def is_in_exec(va):
for start, end in EXEC_SECTIONS:
if start <= va <= end:
return True
return False
def next_inst(data, idx, max_bytes=1000):
"""Yield (offset, instruction, is_32bit) for instructions starting at idx."""
end = min(idx + max_bytes, len(data))
i = idx
while i < end:
if i + 2 > len(data):
break
first16 = struct.unpack('<H', data[i:i+2])[0]
if (first16 & 0x3) != 0x3:
yield (i, first16, False)
i += 2
else:
if i + 4 <= len(data):
inst32 = struct.unpack('<I', data[i:i+4])[0]
yield (i, inst32, True)
i += 4
else:
break
def decode_inst(inst, is_32bit):
"""Return (mnemonic, operands_dict) or None."""
if not is_32bit:
# 16-bit compressed
if (inst & 0xF003) == 0x8002: # c.mv
rd = (inst >> 7) & 0x7
rs2 = (inst >> 10) & 0x7
return ('c.mv', {'rd': rd + 8, 'rs2': rs2 + 8})
if (inst & 0xE003) == 0x6001: # c.addi
rd = (inst >> 7) & 0x7
imm = ((inst >> 2) & 0x3F) | ((inst >> 12) & 0x1) << 6
if imm & 0x40: imm -= 0x80
return ('c.addi', {'rd': rd + 8, 'imm': imm})
return None
else:
opcode = inst & 0x7F
funct3 = (inst >> 12) & 0x7
rd = (inst >> 7) & 0x1F
rs1 = (inst >> 15) & 0x1F
if opcode == 0x13 and funct3 == 0: # addi
imm = (inst >> 20) & 0xFFF
if imm >= 0x800: imm -= 0x1000
return ('addi', {'rd': rd, 'rs1': rs1, 'imm': imm})
if opcode == 0x23 and funct3 == 3: # sd
rs2 = (inst >> 20) & 0x1F
offset = ((inst >> 7) & 0x1F) | ((inst >> 25) & 0x7F) << 5
return ('sd', {'rs1': rs1, 'rs2': rs2, 'offset': offset})
if opcode == 0x03 and funct3 == 3: # ld
offset = (inst >> 20) & 0xFFF
if offset >= 0x800: offset -= 0x1000
return ('ld', {'rd': rd, 'rs1': rs1, 'offset': offset})
if opcode == 0x6F: # jal
imm = ((inst >> 31) & 0x1) << 20 | ((inst >> 12) & 0xFF) << 12 | ((inst >> 20) & 0x1) << 11 | ((inst >> 21) & 0x3FF) << 1
if imm & 0x100000: imm -= 0x200000
return ('jal', {'rd': rd, 'imm': imm})
if opcode == 0x67 and funct3 == 0: # jalr
imm = (inst >> 20) & 0xFFF
if imm >= 0x800: imm -= 0x1000
return ('jalr', {'rd': rd, 'rs1': rs1, 'imm': imm})
if inst == 0x00008067: # ret
return ('ret', {})
return None
def main():
print(f"Reading firmware...")
data = read_binary(FWIMAGE_PATH)
print(f"Binary size: {len(data)} bytes")
functions = []
i = 0
while i < len(data) - 4:
if not is_in_exec(BASE_ADDR + i):
i += 2
continue
# Look for function prologue: addi sp, sp, -N (N >= 32)
if i + 4 <= len(data):
inst32 = struct.unpack('<I', data[i:i+4])[0]
if (inst32 & 0x707F) == 0x0013:
rd = (inst32 >> 7) & 0x1F
rs1 = (inst32 >> 15) & 0x1F
if rd == 2 and rs1 == 2:
imm = (inst32 >> 20) & 0xFFF
if imm >= 0x800:
stack_size = -(imm - 0x1000)
if stack_size >= 32:
# Found potential prologue start
va = BASE_ADDR + i
# Scan forward to verify function structure
saves_s = 0
has_s0_setup = False
ra_save_reg = None
ra_restore_reg = None
has_ret = False
calls = 0
for offset, inst, is_32 in next_inst(data, i + 4, max_bytes=500):
dec = decode_inst(inst, is_32)
if not dec:
continue
mnemonic, ops = dec
# Count sd sX, offset(sp) - callee-saved saves
if mnemonic == 'sd' and ops['rs1'] == 2 and 9 <= ops['rs2'] <= 18:
saves_s += 1
# addi s0, sp, N (frame pointer setup)
if mnemonic == 'addi' and ops['rd'] == 8 and ops['rs1'] == 2:
if ops['imm'] == stack_size:
has_s0_setup = True
# mv sX, ra (save ra to callee-saved reg)
if mnemonic == 'addi' and ops['rd'] >= 9 and ops['rd'] <= 18 and ops['rs1'] == 1 and ops['imm'] == 0:
if ra_save_reg is None:
ra_save_reg = ops['rd']
# c.mv sX, ra
if mnemonic == 'c.mv' and ops['rs2'] == 1 and 8 <= ops['rd'] <= 15:
if ra_save_reg is None:
ra_save_reg = ops['rd']
# mv ra, sX (restore ra from callee-saved reg)
if mnemonic == 'addi' and ops['rd'] == 1 and ops['imm'] == 0 and 9 <= ops['rs1'] <= 18:
ra_restore_reg = ops['rs1']
# c.mv ra, sX
if mnemonic == 'c.mv' and ops['rd'] == 1 and 8 <= ops['rs2'] <= 15:
ra_restore_reg = ops['rs2']
# Function calls
if mnemonic in ('jal', 'jalr'):
calls += 1
# Return
if mnemonic == 'ret':
has_ret = True
break
# Validate: must have prologue elements and either:
# - saves ra to callee-saved reg (if it makes calls)
# - or is a leaf function (no calls)
if saves_s >= 2 and has_s0_setup and has_ret:
if calls == 0 or (ra_save_reg is not None and ra_restore_reg is not None):
functions.append({
"address": f"0x{va:08x}",
"stack_size": stack_size,
"saves": saves_s,
"ra_save_reg": ra_save_reg,
"ra_restore_reg": ra_restore_reg,
"calls": calls,
"type": "non_leaf" if calls > 0 else "leaf"
})
i += 4
continue
i += 2
print(f"Found {len(functions)} functions")
# Deduplicate
seen = set()
unique = []
for f in functions:
if f["address"] not in seen:
seen.add(f["address"])
unique.append(f)
unique.sort(key=lambda x: int(x["address"], 16))
print(f"Unique functions: {len(unique)}")
# Save
with open(f"{OUTPUT_DIR}/functions_final.json", "w") as f:
json.dump(unique, f, indent=2)
with open(f"{OUTPUT_DIR}/function_addresses_final.txt", "w") as f:
for func in unique:
f.write(f"{func['address']} stack={func['stack_size']} saves={func['saves']} calls={func['calls']} ra_save={func.get('ra_save_reg') or 'none'} ra_restore={func.get('ra_restore_reg') or 'none'} type={func['type']}\n")
# Stats
leaf = sum(1 for f in unique if f['type'] == 'leaf')
non_leaf = sum(1 for f in unique if f['type'] == 'non_leaf')
print(f"Leaf functions: {leaf}")
print(f"Non-leaf functions: {non_leaf}")
# Show first 50
print("\nFirst 50 functions:")
for f in unique[:50]:
print(f" {f['address']}: stack={f['stack_size']} saves={f['saves']} calls={f['calls']} ra_save={f.get('ra_save_reg') or 'none'} type={f['type']}")
if __name__ == "__main__":
main()
|
