binutils

Name: binutils
Author: mohitmishra786

304installs19forks

How to install binutils?

mohitmishra786/low-level-dev-skills/binutils

$npx -y skills add mohitmishra786/low-level-dev-skills --skill binutils

Installs into the current project.

Summary

GNU binutils skill for binary manipulation and analysis. Use when using ar for static libraries, strip or objcopy for binary processing, addr2line for converting addresses to source locations, strings for text extraction, or c++filt for C++ name demangling. Activates on queries a

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SKILL.md

1	# GNU Binutils
2
3	## Purpose
4
5	Guide agents through the binutils toolset for binary manipulation: static libraries, stripping, address-to-source mapping, and symbol demangling.
6
7	## Triggers
8
9	- "How do I create a static library?"
10	- "How do I strip a binary but keep a debug file?"
11	- "I have an address from a crash — how do I find the source line?"
12	- "How do I demangle a C++ symbol name?"
13	- "How do I extract/replace sections in a binary?"
14
15	## Workflow
16
17	### 1. `ar` — static library management
18
19	```bash
20	# Create static library
21	ar rcs libfoo.a foo.o bar.o baz.o
22
23	# List contents
24	ar t libfoo.a
25
26	# Extract an object
27	ar x libfoo.a foo.o
28
29	# Add/replace an object
30	ar r libfoo.a newbar.o
31
32	# Delete an object
33	ar d libfoo.a oldbar.o
34
35	# Show symbol index
36	nm libfoo.a
37
38	# Rebuild symbol index (after modifying archive externally)
39	ranlib libfoo.a
40	```
41
42	For LTO archives: use `gcc-ar`/`gcc-ranlib` or `llvm-ar` instead of plain `ar`.
43
44	### 2. `strip` — remove debug info
45
46	```bash
47	# Strip all debug info (reduce binary size)
48	strip --strip-all prog
49
50	# Strip only debug sections (keep symbol table)
51	strip --strip-debug prog
52
53	# Strip unneeded symbols (keep needed for linking)
54	strip --strip-unneeded prog
55
56	# In-place
57	strip prog
58
59	# To a new file
60	strip -o prog.stripped prog
61	```
62
63	### 3. `objcopy` — binary section manipulation
64
65	```bash
66	# Separate debug info from binary
67	objcopy --only-keep-debug prog prog.debug
68	objcopy --strip-debug prog
69
70	# Add debuglink (GDB finds prog.debug automatically)
71	objcopy --add-gnu-debuglink=prog.debug prog
72
73	# Convert binary to another format
74	objcopy -O binary prog prog.bin # raw binary (embedded)
75	objcopy -O srec prog prog.srec # Motorola S-record
76
77	# Add a section from a file
78	objcopy --add-section .resources=data.bin prog
79
80	# Remove a section
81	objcopy --remove-section .comment prog
82
83	# Change section flags
84	objcopy --set-section-flags .data=alloc,contents,load,readonly prog
85
86	# Embed a binary file as a symbol
87	objcopy -I binary -O elf64-x86-64 \
88	--rename-section .data=.rodata,alloc,load,readonly,data,contents \
89	data.bin data.o
90	# Then link data.o; access via _binary_data_bin_start / _binary_data_bin_end
91	```
92
93	### 4. `addr2line` — address to source
94
95	```bash
96	# Convert a crash address to source:line
97	addr2line -e prog -f 0x400a12
98	# Output:
99	# my_function
100	# /home/user/src/main.c:42
101
102	# Multiple addresses
103	addr2line -e prog -f 0x400a12 0x400b34 0x400c56
104
105	# Inline frames (-i)
106	addr2line -e prog -f -i 0x400a12
107
108	# Common use: pipe from backtrace output
109	cat crash.log \| grep '0x[0-9a-f]' \| grep -o '0x[0-9a-f]*' \| \
110	addr2line -e prog -f -i
111	```
112
113	Requires the binary to have debug info (compiled with `-g`). For stripped binaries, use the unstripped version or a `.debug` file.
114
115	### 5. `c++filt` — demangle C++ symbols
116
117	```bash
118	# Demangle a single symbol
119	c++filt _ZN3foo3barEv
120	# Output: foo::bar()
121
122	# Demangle from nm output
123	nm prog \| c++filt
124
125	# Demangle from crash log
126	cat crash.log \| c++filt
127	```
128
129	Alternative: `nm -C prog` (demangle directly in nm).
130
131	### 6. `strings` — extract printable strings
132
133	```bash
134	strings prog # all strings >= 4 chars
135	strings -n 8 prog # minimum length 8
136	strings -t x prog # with offset (hex)
137	strings -t d prog # with offset (decimal)
138
139	# Search for specific strings
140	strings prog \| grep "version"
141	strings prog \| grep "Copyright"
142	```
143
144	### 7. `readelf` and `objdump` quick reference
145
146	(Full coverage in `skills/binaries/elf-inspection`)
147
148	```bash
149	# Symbol lookup for crash address (alternative to addr2line)
150	objdump -d -M intel prog \| grep -A5 "400a12:"
151
152	# Find which object file defines a symbol
153	objdump -t prog \| grep my_function
154	```
155
156	### 8. Cross-binutils
157
158	For cross-compilation, use the target-prefixed versions:
159
160	```bash
161	aarch64-linux-gnu-strip prog
162	aarch64-linux-gnu-objcopy --only-keep-debug prog prog.debug
163	aarch64-linux-gnu-addr2line -e prog 0x400a12
164	arm-none-eabi-nm libfirmware.a
165	```
166
167	For a complete command cheatsheet covering all tools (ar, strip, objcopy, addr2line, strings, c++filt), see [references/cheatsheet.md](references/cheatsheet.md).
168
169	## Related skills
170
171	- Use `skills/binaries/elf-inspection` for `readelf`, `nm`, `ldd`, `objdump` inspection
172	- Use `skills/binaries/linkers-lto` for linker flags and LTO
173	- Use `skills/debuggers/core-dumps` for debug file management with `objcopy --add-gnu-debuglink`

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Type

binutils

304installs19forks

View on GitHub

How to install binutils?

mohitmishra786/low-level-dev-skills/binutils

$npx -y skills add mohitmishra786/low-level-dev-skills --skill binutils

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# GNU Binutils
2
3	## Purpose
4
5	Guide agents through the binutils toolset for binary manipulation: static libraries, stripping, address-to-source mapping, and symbol demangling.
6
7	## Triggers
8
9	- "How do I create a static library?"
10	- "How do I strip a binary but keep a debug file?"
11	- "I have an address from a crash — how do I find the source line?"
12	- "How do I demangle a C++ symbol name?"
13	- "How do I extract/replace sections in a binary?"
14
15	## Workflow
16
17	### 1. `ar` — static library management
18
19	```bash
20	# Create static library
21	ar rcs libfoo.a foo.o bar.o baz.o
22
23	# List contents
24	ar t libfoo.a
25
26	# Extract an object
27	ar x libfoo.a foo.o
28
29	# Add/replace an object
30	ar r libfoo.a newbar.o
31
32	# Delete an object
33	ar d libfoo.a oldbar.o
34
35	# Show symbol index
36	nm libfoo.a
37
38	# Rebuild symbol index (after modifying archive externally)
39	ranlib libfoo.a
40	```
41
42	For LTO archives: use `gcc-ar`/`gcc-ranlib` or `llvm-ar` instead of plain `ar`.
43
44	### 2. `strip` — remove debug info
45
46	```bash
47	# Strip all debug info (reduce binary size)
48	strip --strip-all prog
49
50	# Strip only debug sections (keep symbol table)
51	strip --strip-debug prog
52
53	# Strip unneeded symbols (keep needed for linking)
54	strip --strip-unneeded prog
55
56	# In-place
57	strip prog
58
59	# To a new file
60	strip -o prog.stripped prog
61	```
62
63	### 3. `objcopy` — binary section manipulation
64
65	```bash
66	# Separate debug info from binary
67	objcopy --only-keep-debug prog prog.debug
68	objcopy --strip-debug prog
69
70	# Add debuglink (GDB finds prog.debug automatically)
71	objcopy --add-gnu-debuglink=prog.debug prog
72
73	# Convert binary to another format
74	objcopy -O binary prog prog.bin # raw binary (embedded)
75	objcopy -O srec prog prog.srec # Motorola S-record
76
77	# Add a section from a file
78	objcopy --add-section .resources=data.bin prog
79
80	# Remove a section
81	objcopy --remove-section .comment prog
82
83	# Change section flags
84	objcopy --set-section-flags .data=alloc,contents,load,readonly prog
85
86	# Embed a binary file as a symbol
87	objcopy -I binary -O elf64-x86-64 \
88	--rename-section .data=.rodata,alloc,load,readonly,data,contents \
89	data.bin data.o
90	# Then link data.o; access via _binary_data_bin_start / _binary_data_bin_end
91	```
92
93	### 4. `addr2line` — address to source
94
95	```bash
96	# Convert a crash address to source:line
97	addr2line -e prog -f 0x400a12
98	# Output:
99	# my_function
100	# /home/user/src/main.c:42
101
102	# Multiple addresses
103	addr2line -e prog -f 0x400a12 0x400b34 0x400c56
104
105	# Inline frames (-i)
106	addr2line -e prog -f -i 0x400a12
107
108	# Common use: pipe from backtrace output
109	cat crash.log \| grep '0x[0-9a-f]' \| grep -o '0x[0-9a-f]*' \| \
110	addr2line -e prog -f -i
111	```
112
113	Requires the binary to have debug info (compiled with `-g`). For stripped binaries, use the unstripped version or a `.debug` file.
114
115	### 5. `c++filt` — demangle C++ symbols
116
117	```bash
118	# Demangle a single symbol
119	c++filt _ZN3foo3barEv
120	# Output: foo::bar()
121
122	# Demangle from nm output
123	nm prog \| c++filt
124
125	# Demangle from crash log
126	cat crash.log \| c++filt
127	```
128
129	Alternative: `nm -C prog` (demangle directly in nm).
130
131	### 6. `strings` — extract printable strings
132
133	```bash
134	strings prog # all strings >= 4 chars
135	strings -n 8 prog # minimum length 8
136	strings -t x prog # with offset (hex)
137	strings -t d prog # with offset (decimal)
138
139	# Search for specific strings
140	strings prog \| grep "version"
141	strings prog \| grep "Copyright"
142	```
143
144	### 7. `readelf` and `objdump` quick reference
145
146	(Full coverage in `skills/binaries/elf-inspection`)
147
148	```bash
149	# Symbol lookup for crash address (alternative to addr2line)
150	objdump -d -M intel prog \| grep -A5 "400a12:"
151
152	# Find which object file defines a symbol
153	objdump -t prog \| grep my_function
154	```
155
156	### 8. Cross-binutils
157
158	For cross-compilation, use the target-prefixed versions:
159
160	```bash
161	aarch64-linux-gnu-strip prog
162	aarch64-linux-gnu-objcopy --only-keep-debug prog prog.debug
163	aarch64-linux-gnu-addr2line -e prog 0x400a12
164	arm-none-eabi-nm libfirmware.a
165	```
166
167	For a complete command cheatsheet covering all tools (ar, strip, objcopy, addr2line, strings, c++filt), see [references/cheatsheet.md](references/cheatsheet.md).
168
169	## Related skills
170
171	- Use `skills/binaries/elf-inspection` for `readelf`, `nm`, `ldd`, `objdump` inspection
172	- Use `skills/binaries/linkers-lto` for linker flags and LTO
173	- Use `skills/debuggers/core-dumps` for debug file management with `objcopy --add-gnu-debuglink`

People who liked this also viewed

6 picks

Type