forked from Imagelibrary/rtems
92b67b18d7
PR 496/bsps * startup/sbrk.c: New file. * startup/bspstart.c: This patch implements 'sbrk' for the powerpc-shared BSP to work around what's known as the '32Mb problem' in combination with run-time loaded code. GCC normally generates (PowerPC) code doing 'short jumps' which requires all text segments being in the same 32Mb area of memory. However, some run-time loaders use (e.g. heap-) memory violating the stated limitation on hardware with more than 32Mb of memory. (NOTE: portable loaders are probably not even aware of this GCC/CPU specific problem.) This patch implements a simple workaround: At boot time, the system is only provided with 32Mb of memory. The user is supposed to load all necessary modules prior to that limit being exhausted. Once that happens, newlib/malloc end up trying to 'sbrk()' for more memory and the implementation provided by this patch will then make the rest of the physical memory available.