bionic/libc
Elliott Hughes 66c033868f am c64c1b49: am ad8ff472: am c1eb7619: am 440e417d: Merge "Add dependencies on all the makefiles."
* commit 'c64c1b49fd5c51b1b6e87d88b233d23fa172d372':
  Add dependencies on all the makefiles.
2012-08-13 16:10:31 -07:00
..
arch-arm crtend*: Add GNU_STACK note 2012-08-10 14:12:00 -07:00
arch-mips Add unshare() syscall. 2012-08-10 12:57:43 -07:00
arch-x86 Add unshare() syscall. 2012-08-10 12:57:43 -07:00
bionic Handle naming for system uids running as secondary users 2012-08-13 13:35:31 -07:00
docs libc: Fix the definition of SIGRTMAX 2010-12-20 15:58:06 +01:00
include Merge "MIPS support to sigsuspend and sigwait routines" 2012-08-10 15:05:36 -07:00
inet inet_ntop: pass the size of tmp to snprintf() 2012-06-11 16:00:52 -07:00
kernel am 35dcf19b: am 66fba009: Merge "Update arch-mips/asm/unistd.h for the newer syscalls" 2012-08-13 16:03:16 -07:00
netbsd am c5cab345: am 028ccf5d: Merge "Avoid multiple dns lookups for the same query" 2012-06-12 15:56:29 -07:00
private Clean up the linker a bit, remove prelinking support. 2012-08-07 11:41:10 -07:00
regex Remove compiler warnings when building Bionic. 2010-06-22 17:51:41 -07:00
stdio vfprintf: fix spelling. 2012-07-25 16:01:38 -07:00
stdlib fix __cxa_finalize() implementation to be thread safe. 2012-07-31 12:30:28 +02:00
string Revert "Revert "Switch to NetBSD's strxfrm(3)."" 2012-08-10 12:10:10 -07:00
tools Auto-generate a complete NOTICE file. 2012-08-09 16:05:31 -07:00
tzcode libc: remove private declarations from <time.h> and <resolv.h> 2012-01-13 14:24:08 +01:00
unistd MIPS support to sigsuspend and sigwait routines 2012-08-09 18:51:19 -07:00
upstream-netbsd Revert "Revert "Switch to NetBSD's strxfrm(3)."" 2012-08-10 12:10:10 -07:00
wchar wchar.h: improve wchar_t support in Bionic 2010-06-15 07:04:41 -07:00
zoneinfo Add dependencies on all the makefiles. 2012-08-13 14:06:05 -07:00
Android.mk am c64c1b49: am ad8ff472: am c1eb7619: am 440e417d: Merge "Add dependencies on all the makefiles." 2012-08-13 16:10:31 -07:00
CAVEATS auto import from //depot/cupcake/@135843 2009-03-03 19:28:35 -08:00
MODULE_LICENSE_BSD auto import from //depot/cupcake/@135843 2009-03-03 19:28:35 -08:00
NOTICE Revert "Revert "Switch to NetBSD's strxfrm(3)."" 2012-08-10 12:10:10 -07:00
README Add an 's and a . to the bionic/libc README. 2009-07-23 17:41:47 -07:00
SYSCALLS.TXT Merge "MIPS support to sigsuspend and sigwait routines" 2012-08-10 15:05:36 -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.