dummy_malloc: Check if sbrk() fails ...

Add code to check if sbrk() fails as well as setting appropriate
'errno' for users that may rely on it for error reporting.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

dummy_malloc: Make use of PTR_ALIGN ...

Drop explicit type cast and alignement code in favor of PTR_ALIGN

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

tlsf_malloc: dummy_malloc: Share code for calloc() ...

Calloc() implementation for TLSF does not correctly check for malloc()
failure which can result in a NULL pointer exception when trying to
calloc() extra large buffers.

Since both TLSF and dummy malloc implementations of calloc() are
exactly the same, pick implementation for the latter (which does
aforementioned check) and share it between the two.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

xfuncs: Be more informative when out of memory panic occurs ...

When one of the xfuncs panics we can be a bit more informative. We
can at least print the amount of bytes we wanted to allocate and
how much memory we have left.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

dummy malloc: Add licence header ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

dummy_malloc: add calloc support ...

needed to use menu framework

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

add dummy_malloc functions ...

For some environments the dummy malloc functions offer a very small
alternative implementation. malloc will get its memory from sbrk()
and never frees memory again.
This of course is not suitable for interactive environments and thus
depends on CONFIG_SHELL_NONE

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>