Racket Binutils
1 Binary Objects
bin:  object
bin:  section
bin:  symbol
bin:  relocation
2 Linking
link-object/  local/  relative
3 Dynamic Loading
dynamic-object<%>
symbols
symbol-ref
load-object
4 ELF Support
4.1 Reading and Writing
read-elf
write-elf
4.2 Conversion
elf->bin:  object
bin:  object->elf
4.3 ELF Data Structures
elf%
repack!
4.4 Utilities
system-elf-class
6.12

Racket Binutils

This package is not stable, and is likely to break compatibility in the future.

 (require binutils) package: binutils

1 Binary Objects

struct

(struct bin:object (sections)
    #:extra-constructor-name make-bin:object)
  sections : (listof bin:section?)
Represents a binary object.

struct

(struct bin:section (name
    size
    writable?
    executable?
    data
    symbols
    relocations)
    #:extra-constructor-name make-bin:section)
  name : (or/c bytes? #f)
  size : (or/c exact-nonnegative-integer? #f)
  writable? : boolean?
  executable? : boolean?
  data : (or/c bytes? #f)
  symbols : (listof bin:symbol?)
  relocations : (listof bin:relocation?)
Represents a section of a binary object.

struct

(struct bin:symbol (name value size binding type)
    #:extra-constructor-name make-bin:symbol)
  name : symbol?
  value : exact-integer?
  size : (or/c exact-nonnegative-integer? #f)
  binding : (one-of/c 'local 'global 'weak #f)
  type : (one-of/c 'object 'function #f)
Represents a symbol for linking.

struct

(struct bin:relocation (offset size symbol type addend)
    #:extra-constructor-name make-bin:relocation)
  offset : exact-nonnegative-integer?
  size : exact-nonnegative-integer?
  symbol : symbol?
  type : (one-of/c 'address 'offset 'value 'size)
  addend : exact-integer?
Represents a relocation.

2 Linking

procedure

(link-object/local/relative obj)  bin:object?

  obj : bin:object?
Resolves local relative references in obj.

3 Dynamic Loading

This is unsafe (particularly if there are bugs, which is likely) - it could cause crashes or worse!

Represents an object which has been loaded into memory.

method

(send a-dynamic-object symbols)  (listof symbol?)

Returns a list of symbols exported by the object.

method

(send a-dynamic-object symbol-ref name)  cpointer?

  name : symbol?
Returns a pointer to the requested symbol. This may be cast into a function type.

procedure

(load-object obj)  (is-a?/c dynamic-object<%>)

  obj : bin:object?
Loads obj into memory.

4 ELF Support

 (require binutils/elf) package: binutils

4.1 Reading and Writing

procedure

(read-elf [in])  (is-a?/c elf%)

  in : input-port? = (current-input-port)
Reads an ELF binary from in.

procedure

(write-elf v [out])  void?

  v : (is-a?/c elf%)
  out : output-port? = (current-output-port)
Writes v as an ELF binary to out.

4.2 Conversion

procedure

(elf->bin:object elf)  (bin:object?)

  elf : (is-a?/c elf%)
Converts elf to a generic object. Some information will be lost in this process.

procedure

(bin:object->elf obj)  (is-a?/c elf%)

  obj : bin:object?
Converts obj to an ELF object.

4.3 ELF Data Structures

These classes represent the ELF format. For details, see the ELF specification and the source code of this module.

class

elf% : class?

  superclass: object%

  extends: binary<%>

method

(send an-elf repack!)  void?

Adjusts sizes and offsets to fit the contents of the object.

4.4 Utilities

procedure

(system-elf-class)  (or/c 'elf32 'elf64)

Returns the appropriate ELF class for the current processor.