I would like to request the addition of special,
verbose warning messages printed by the linker, when
certain well-known symbols are not resolved. Here's
two that commonly come up as questions on the user mail
?ASlink-Warning-Undefined Global '_putchar' referenced
by module 'vprintf'
The SDCC library does not provide a putchar() function.
functions preform all output by calling putchar(). You
a putchar() function in your code, which is specific to
hardware can output characters (serial port, LCD, etc).
refer to the SDCC manual and device/examples directory
'__sdcc_external_startup' referenced by module 'test'
This error usually indicates that the SDCC standard
library is not
installed properly. The SDCC library contains a default
_sdcc_external_startup() that simply returns. When
is undefined, usually the library files are missing,
are in a different location. In the latter case, you
can use the -I
command line option to specify the library directory.