bionic/libc
David Turner 1dae997ca4 am a57270b6: am 56baceca: Merge "Update X86 Bionic CRT files for unwind/exceptions"
* commit 'a57270b6ab2978764920ade17448f94875249001':
  Update X86 Bionic CRT files for unwind/exceptions
2011-06-06 12:57:00 -07:00
..
arch-arm am a7a9dddb: Merge "bionic: Add ARM optimized strcmp()" 2011-05-17 04:47:09 -07:00
arch-sh Add support for the utimensat(2) syscall to bionic. 2011-03-24 18:18:48 -07:00
arch-x86 am 56baceca: Merge "Update X86 Bionic CRT files for unwind/exceptions" 2011-06-06 11:32:38 -07:00
bionic Implement getpwnam_r(3) and getpwuid_r(3). 2011-05-27 00:52:21 -07:00
docs libc: Fix the definition of SIGRTMAX 2010-12-20 15:58:06 +01:00
include libc: enable IPTOS_MINCOST, fixup gethostbyaddr() proto. 2011-05-18 16:53:23 -07:00
inet added missing ether_aton and ether_ntoa 2010-08-25 08:46:23 -07:00
kernel Merge "sound/asound.h: add header for ALSA" 2011-05-26 09:37:32 -07:00
netbsd libc: enable IPTOS_MINCOST, fixup gethostbyaddr() proto. 2011-05-18 16:53:23 -07:00
private Update X86 Bionic CRT files for unwind/exceptions 2011-05-24 13:31:50 -07:00
regex Remove compiler warnings when building Bionic. 2010-06-22 17:51:41 -07:00
stdio am c5c84c86: Merge "vfscanf: Add support for L type modifier for long long" 2011-05-17 04:47:06 -07:00
stdlib Bug 3330205 Thread safety for bignum powers of 5 2011-01-17 11:32:11 -08:00
string Use more optimized version of memmove 2011-02-03 15:17:13 +01:00
tools checksyscalls fix to handle "__ARM_NR_... (__ARM_NR_BASE+0x...)" 2011-04-05 20:17:34 -07:00
tzcode Bug 3330205 Thread safe strptime implementation 2011-01-11 09:33:04 -08:00
unistd Add some missing includes. 2011-03-21 20:01:03 -07:00
wchar
zoneinfo Update to tzdata2011g. 2011-05-06 10:57:36 -07:00
Android.mk am a9e409a0: am a7a9dddb: Merge "bionic: Add ARM optimized strcmp()" 2011-05-17 04:51:45 -07:00
CAVEATS
Jamfile
MODULE_LICENSE_BSD
NOTICE Clean up NOTICE files. 2010-10-19 15:12:40 -07:00
README
SYSCALLS.TXT Add support for the utimensat(2) syscall to bionic. 2011-03-24 18:18:48 -07:00

Welcome to Bionic, Android's small and custom C library for the Android
platform.

Bionic is mainly a port of the BSD C library to our Linux kernel with the
following additions/changes:

- no support for locales
- no support for wide chars (i.e. multi-byte characters)
- its own smallish implementation of pthreads based on Linux futexes
- support for x86, ARM and ARM thumb CPU instruction sets and kernel interfaces

Bionic is released under the standard 3-clause BSD License

Bionic doesn't want to implement all features of a traditional C library, we only
add features to it as we need them, and we try to keep things as simple and small
as possible. Our goal is not to support scaling to thousands of concurrent threads
on multi-processors machines; we're running this on cell-phones, damnit !!

Note that Bionic doesn't provide a libthread_db or a libm implementation.


Adding new syscalls:
====================

Bionic provides the gensyscalls.py Python script to automatically generate syscall
stubs from the list defined in the file SYSCALLS.TXT. You can thus add a new syscall
by doing the following:

- edit SYSCALLS.TXT
- add a new line describing your syscall, it should look like:

   return_type  syscall_name(parameters)    syscall_number

- in the event where you want to differentiate the syscall function from its entry name,
  use the alternate:

   return_type  funcname:syscall_name(parameters)  syscall_number

- additionally, if the syscall number is different between ARM and x86, use:

   return_type  funcname[:syscall_name](parameters)   arm_number,x86_number

- a syscall number can be -1 to indicate that the syscall is not implemented on
  a given platform, for example:

   void   __set_tls(void*)   arm_number,-1


the comments in SYSCALLS.TXT contain more information about the line format

You can also use the 'checksyscalls.py' script to check that all the syscall
numbers you entered are correct. It does so by looking at the values defined in
your Linux kernel headers. The script indicates where the values are incorrect
and what is expected instead.