avr-libc: add support for avr-libc C library

This commit adds support for the avr-libc C library.
According to the project page at http://www.nongnu.org/avr-libc , the
avr-libc package provides a subset of the standard C library for Atmel
AVR 8-bit RISC microcontrollers. In addition, the library provides the
basic startup code needed by most applications.

Support for this library in crosstool-ng is only enabled for the AVR
8-bit target.

The avr-libc manual and most distributions build the AVR 8-bit gcc
toolchain with the "avr" (non-canonical) target.
Some experimentation also led to the conclusion that other (canonical)
targets are not very well supported, so we force the "avr" target for
crosstool-ng as well.

The manual also recommends building avr-libc after the final gcc build.
To accomplish this with crosstool-ng, a new do_libc_post_cc step is
added, in which currently only avr-libc performs its build, and is a
no-op for the other libc options.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/scripts/build/libc/glibc.sh b/scripts/build/libc/glibc.sh
index 672e6725..39dbe01d 100644
--- a/scripts/build/libc/glibc.sh
+++ b/scripts/build/libc/glibc.sh
@@ -665,3 +665,7 @@ do_libc_locales() {
                           install_root="${CT_SYSROOT_DIR}"          \
                           localedata/install-locales
 }
+
+do_libc_post_cc() {
+    :
+}