Since both platforms now have their VBR and gint-specific data loaded
along the add-in's data, the .gint.data section is entirely unused.
The .gint.bss section is still used for uninitialized objects (it has
different semantics than .bss which is initially cleared) and the
.gint.data.sh3 and .gint.bss.sh3 sections that are dropped on the
SH4-only fx-CG 50 are also still used.
I have recenty discovered that the so-called "rram" section used by gint
to store its VBR space and a couple memory structures gets overwritten
when returning to the main menu. It is thus necessary to get rid of it
and store that data somewhere else.
My current lead is to have it at the start of the static RAM by querying
its address in the TLB. However, the static RAM is very small on SH3
(8k) so the VBR must be made more compact.
This change elaborates the event code translation scheme used on SH3 to
emulate SH4 event codes. It is now used to translate the event codes to
a gint-specific VBR layout that leaves no gaps and thus reduces the size
of the VBR space. The gint_inthandler() method has to be modified for
every new SH3 interrupt to maintain this scheme.
* Removed .pretext sections since the TLB is now entirely dynamic; left
only .text.entry for the start symbol.
* Reworked the main files of src/core to move the INTC to its own driver
and let the kernel handle only VBR space and CPU (now: VBR & CPUOPM).
* Moved src/core/gint.c to src/core/kernel.c and centralized all driver
loops that save or restore context for more robustness. This leaves
the callbacks of cpu_setVBR() (formerly gint_setvbr()) pretty short.
* Coalesced gint_switch_out() and gint_switch_in() into a single
function callback for cpu_setVBR().
* Added an abstraction of interrupt signals as an enumerated value so
that drivers no longer hardcode the IPR and IMR numbers and bits,
sometimes even with isSH3() due to differences in the SH7705.
* Changed the interrupt blocking method in cpu_setVBR() from SR.BL=1 to
SR.IMASK=15 so that TLB misses are still handled. This removes the
need for callback functions to be GMAPPED.
* Moved gint_osmenu() and its utilities to a new file src/core/osmenu.c.
