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.
This change introduces two new functions dtext_opt() and dprint_opt()
that have both color and alignment options. The regular dtext() and
dprint() have been changed to always used bg=C_NONE which is what most
calls want.
This change ports the TLB management system to fx9860g through %003.
This raises the size limit for add-ins to about 500k.
Because SH3 fx9860g does not have ILRAM, the GMAPPED attribute has been
made to generate content to a .gint.mapped section which is sent to the
P1 RAM section historically dubbed "real ram" in which gint's data and
VBR are installed. (Now that I think about it, gint's data should try to
go to normal RAM instead to reduce pressure on this invasion.)
Return-to-menu was also fixed on both platforms by narrowing down the
need for code to remain mapped to the chance of running it with
interrupts disabled. The natural distribution of GMAPPED under this
criterion showed that _gint_setvbr had been left under TLB control;
moving it to the proper RAM area fixed gint switches.
Finally, an omission in the bound checks for mappable TEA addresses (TEA
>= 0x00300000) prevented the appearance of a non-interactible System
ERROR popup when some unmapped addresses are accessed.
This version still does not enable interrupts in timer callbacks,
exposing any application to a crash if a timer underflows while its
callback is not mapped. It is not suitable for any stable application!
This change adds a TLB miss handler that calls __TLB_LoadPTEH() and
removes the startu mapping of add-in pages in the explore() routine of
src/core/start.c.
Note that calling __TLB_LoadPTEH() manually might unexpectedly lead to a
TLB multihit problem as the requested page might be accidentally loaded
by a TLB miss in the code that loads it. A TLB multihit is a platform
reset, so this function should always be considered unsafe to call
(unless the calling code is in a combination of P1 space and ILRAM).
This change also moves a lot of functions out of the .pretext section,
notably topti, as this was designed to allow panic messages when the
add-in couldn't be mapped entirely. By contrast, a GMAPPED macro has
been defined to mark crucial kernel code and data that must remain
mapped at all times. This currently puts the data in ILRAM because
static RAM is not executable. An alternative will have to be found for
SH3-based fx9860g machines.
This version still does not allow TLB misses in timer callbacks and
breaks return-to-menu in a severe way! It is not suitable for any
stable application!
This is an obvious requirement for the interrupt routine, which was
forgotten and only surfaced when I used a timer callback started with
multiplications in an innocent add-in. r0..r7 are saved automatically,
which leaves pr, gbr, mach et macl susceptible to corruption by the
interrupt handler.
t6k11: use the gint array for variant detection
r61524: use true triple buffering by default
display: define DWIDTH and DHEIGHT
display: add C_RGB(r,g,b) (0 ≤ r,g,b ≤ 31) [fxcg50]
This macro used to protect the declaration of the [vram] variable of
gint. This variable was short to keep drawing functions short but could
clutter the namespace.
That being said, it's even better to just [#define vram gint_vram] if
you need. This change renames the variable to [gint_vram], exposes it
whenever <gint/display.h> is included, and removes the GINT_NEED_VRAM
macro altogether.
This change introduces two new mechanismes for executing user code when
an exception occurs.
* This first is the custom panic message, which usually displays "System
ERROR". The function that performs this task can now be user-defined.
It is also run in user mode because the exception handler rte's into
it, allowing it to execute any kind of interrupt-inducing task. The
behavior is undefined if this function raises an exception.
* The second is an exception-catching function, which (when set) is
called every time an exception occurs, and is granted the chance of
handling the exception to continue execution normally. It can be used
in various ways, the most primitive of which is recording the
exception and going back. It runs in interrupt mode and must not raise
any kind of exception.
This change introduces exception handlers that default to a fatal error
with an on-screen description of the exception and some debugging
information.
It also adds the dprint() function as a definitely-needed helper and
removes bootlog_unmapped() by using the exception handler for the fatal
error display. (Also printf() is now required in all gint add-ins; this
is sad, but space is not as much of a constraint as debugging.)
Finally, the exception handler is used to handle an interrupt which is
an exception in practice, the DMA address error. On fx-CG 50, additional
DMA-related information is displayed on the screen. This is left out on
fx-9860G as there is not enough space.
Lephe
lephe