* Change gint_inth_callback()
* Add intc_handler_function() to use C functions as handlers instead of
writing assembler, and use it in the RTC and USB
* Revisit the TMU handlers, which after moving out the callbacks, now
fit into 3 gates (great!), and adapt the ETMU handler
* Improve the timer driver (less code = better code, removed magic
constants assuming the VBR layout on SH3/SH4, etc.)
* Remove 2 gates and a gap from the compact scheme on SH3
* Define timer_configure() to replace timer_setup(), which could not be
cleanly updated to support GINT_CALL()
* Replace rtc_start/stop_timer with rtc_periodic_enable/disable, which
is less confusing because of ETMU being "RTC timers"
Changes in the driver and world system:
* Rewrite driver logic to include more advanced concepts. The notion of
binding a driver to a device is introduced to formalize wait(); power
management is now built-in instead of being handled by the drivers
(for instance DMA). The new driver model is described in great detail
in <gint/drivers.h>
* Formalized the concept of "world switch" where the hardware state is
saved and later restored. As a tool, the world switch turns out to be
very stable, and allows a lot of hardware manipulation that would be
edgy at best when running in the OS world.
* Added a GINT_DRV_SHARED flag for drivers to specify that their state
is shared between worlds and not saved/restored. This has a couple of
uses.
* Exposed a lot more of the internal driver/world system as their is no
particular downside to it. This includes stuff in <gint/drivers.h>
and the driver's state structures in <gint/drivers/states.h>. This is
useful for debugging and for cracked concepts, but there is no
API stability guarantee.
* Added a more flexible driver level system that allows any 2-digit
level to be used.
Feature changes:
* Added a CPU driver that provides the VBR change as its state save.
Because the whole context switch relied on interrupts being disabled
anyway, there is no longer an inversion of control when setting the
VBR; this is just part of the CPU driver's configuration. The CPU
driver may also support other features such as XYRAM block transfer
in the future.
* Moved gint_inthandler() to the INTC driver under the name
intc_handler(), pairing up again with intc_priority().
* Added a reentrant atomic lock based on the test-and-set primitive.
Interrupts are disabled with IMASK=15 for the duration of atomic
operations.
* Enabled the DMA driver on SH7305-based fx-9860G. The DMA provides
little benefit on this platform because the RAM is generally faster
and buffers are ultimately small. The DMA is still not available on
SH3-based fx-9860G models.
* Solved an extremely obnoxious bug in timer_spin_wait() where the
timer is not freed, causing the callback to be called when interrupts
are re-enabled. This increments a random value on the stack. As a
consequence of the change, removed the long delays in the USB driver
since they are not actually needed.
Minor changes:
* Deprecated some of the elements in <gint/hardware.h>. There really is
no good way to "enumerate" devices yet.
* Deprecated gint_switch() in favor of a new function
gint_world_switch() which uses the GINT_CALL abstraction.
* Made the fx-9860G VRAM 32-aligned so that it can be used for tests
with the DMA.
Some features of the driver and world systems have not been implemented
yet, but may be in the future:
* Some driver flags should be per-world in order to create multiple
gint worlds. This would be useful in Yatis' hypervisor.
* A GINT_DRV_LAZY flag would be useful for drivers that don't want to
be started up automatically during a world switch. This is relevant
for drivers that have a slow start/stop sequence. However, this is
tricky to do correctly as it requires dynamic start/stop and also
tracking which world the current hardware state belongs to.
This change adds a new TMU function timer_spinwait() which waits for a
timer to raise its UNF flag. This makes it possible to wait even when
interrupts are disabled.
This is used by the new CPG function sleep_us_spin() which waits for a
given delay without using interrupts. This is currently used in SPU
initialization.
This commit introduces a large architectural change. Unlike previous
models of the fx-9860G series, the G-III models have a new user RAM
address different from 8801c000. The purpose of this change is to
dynamically load GMAPPED functions to this address by querying the TLB,
and call them through a function pointer whose address is determined
when loading.
Because of the overhead of using a function pointer in both assembly and
C code, changes have been made to avoid GMAPPED functions altogether.
Current, only cpu_setVBR() and gint_inth_callback() are left, the second
being used specifically to enable TLB misses when needed.
* Add a .gint.mappedrel section for the function pointers holding
addresses to GMAPPED functions; add function pointers for
cpu_setVBR() and gint_inth_callback()
* Move rram to address 0 instead of the hardcoded 0x8801c000
* Load GMAPPED functions at their linked address + the physical address
user RAM is mapped, to and compute their function pointers
* Remove the GMAPPED macro since no user function needs it anymore
* Add section flags "ax" (code) or "aw" (data) to every custom .section
in assembler code, as they default to unpredictable values that can
cause the section to be marked NOLOAD by the linker
* Update the main kernel, TMU, ETMU and RTC interrupt handlers to use
the new indirect calling method
This is made possible by new MMU functions giving direct access to the
physical area behind any virtualized page.
* Add an mmu_translate() function to query the TLB
* Add an mmu_uram() function to access user RAM from P1
The exception catching mechanism has been modified to avoid the use of
GMAPPED functions altogether.
* Set SR.BL=0 and SR.IMASK=15 before calling exception catchers
* Move gint_exc_skip() to normal text ROM
* Also fix registers not being popped off the stack before a panic
The timer drivers have also been modified to avoid GMAPPED functions.
* Invoke timer_stop() through gint_inth_callback() and move it to ROM
* Move and expand the ETMU driver to span 3 blocks at 0xd00 (ETMU4)
* Remove the timer_clear() function by inlining it into the ETMU handler
(TCR is provided within the storage block of each timer)
* Also split src/timer/inth.s into src/timer/inth-{tmu,etmu}.s
Additionally, VBR addresses are now determined at runtime to further
reduce hardcoded memory layout addresses in the linker script.
* Determine fx-9860G VBR addresses dynamically from mmu_uram()
* Determine fx-CG 50 VBR addresses dynamically from mmu_uram()
* Remove linker symbols for VBR addresses
Comments and documentation have been updated throughout the code to
reflect the changes.
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 moves interrupt handler from VBR + 0x640 to VBR + 0x200, in
the gap between the exception and TLB miss handlers.
This new scheme is not limited to VBR+0x200 .. VBR+0x400 as new large
block numbers can be used to jump over the TLB miss handler and the
interrupt handler entry points.
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.
This commit minimally changes the signature of timer_setup() to greatly
simplify timer management, allowing to user to let the library choose
available timers dynamically depending on the settings.
* 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.
This change includes three reliability improvements in handlers:
1. TMU handlers now actively check for the UNF flag to go low rather
than expecting it to do so right away.
2. CPUOPM.INTMU is now set so that IMASK it updated at every interrupt
(which is absolutely required for nested interrupts!).
3. gint_inth_callback() no longer performs transfers between user bank
and kernel bank while in user bank, because this is when interrupts
are enabled and thus likely to corrupt the kernel bank; rather, it
now does it while in kernel bank with interrupts disabled.
This change fixes a never-should-have-worked problem where the ETMU
interrupt handler loses track of the timer ID before attempting to call
timer_stop(), resulting in complete nonsense.
And also a similar problem in timer_wait().
This change enables interrupts within timer callbacks, making it
possible to load pages to MMU while handling a timer underflow. The call
to TLB_LoadPTEH() has been moved directly into the VBR handler to avoid
jumping to ILRAM for a short call on SH4.
The TMU and ETMU handlers have been changed to callback through a new
function gint_inth_callback() that saves the user bank and a few
registers, then invokes the callback with interrupts enabled and in user
bank; until now, callbacks were invoked with interrupts disabled and in
kernel bank. Note that IMASK is still set so a callback can only be
interrupted by a high-priority interrupt.
A timer_wait() function has also been added to simplify tests that
involve timers. Finally, the priority level of the TMU0 underflow
interrupt has been set to 13 (as per the comments) instead of 7.
This version is the first stable version that handles TLB misses
transparently for large add-ins. It is suitable for every gint
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!
The unload() function is not very relevant for drivers because hardware
state is managed by ctx_save() and ctx_restore() and software state is
managed by underlying drivers when there are dependencies.
For now, it's been replaced with a wait() function that allows drivers
to not be interrupted at any point. It is currently used by the DMA to
wait for ongoing transfers to finish before disabling interrupts (which
would prevent the transfer end from being detected) and switching in and
out of gint.
* Add the gint_switch() function which executes user-provided code from
the system (CASIOWIN) context.
* Added interrupt masks to the core context (should have been there long
ago).
* Added the gint_osmenu() function that switches out of gint to invoke
GetKeyWait() and inject KEY_CTRL_MENU to trigger the main menu. This
uses many CASIOWIN syscalls, but we don't care because gint is unloaded.
Trickery is used to catch the key following the return in the add-in
and/or display a new application frame before GetKeyWait() even finishes
after coming back. This is only available on fx9860g for now.
* Removed any public syscall definition to clear up interfaces.
* Patched the DMA interruption problem in a weird way on fxcg50, a
driver function will be used to do that properly eventually.
* Changed the driver model to save driver contexts in preallocated
spaces instead of on the stack for overall less risk.
* Enabled return-to-menu with the MENU key on fx9860g in getkey().
* Changed the keyboard driver to emit releases before presses, as a
return-to-menu acts as a press+release of different keys in a single
driver frame, which confuses getkey().
* Fixed a really stupid bug in memcpy() that made the function really
not work.
Improvements in the timer driver:
* Expose ETMU modules as SH7705_TMU and SH7305_TMU in <gint/mpu/tmu.h>.
* Remove the timer_t structures, using SH*_ETMU and SH*_TMU instead.
Only interrupt gate entries are left hardcoded.
* Discovered that not only every write to the TCNT or TCR of an ETMU
takes about 1/32k of a second (hinting at registers being powered by
the same clock as the timer), but every write occuring while a previous
write is pending is *lost*. This led to terrible bugs when switching
ETMU contexts too fast in gint_switch().
* Removed an internal timer_address() function.
* Overall simplified the handling of timers and the initialization step.
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 commit introduces three timer driver changes:
* Export the definitions of the timer structures to a detailed header at
<gint/mpu/tmu.h>, and re-use them in the driver.
This integration is still limited as the driver keeps its own address
definitions and event codes.
* Clean the timer stop routine that is used in the interrupt handler. Up
until now the interrupt handler would only stop TSTR, which is not
enough to cleanly leave the timer (need TCOR=TCNT=-1) and is not even
sound with respect to gint's semantics as UNIE stays enabled so the
timer is not made available again.
The interrupt handler now calls into C code when the timer stop
condition is met (callback returns non-zero) to keep this clean. This
unsurprisingly solves problems that occurred in certain situations
when a timer was used repeatedly.
* Expose timer addresses using a timer_address() function, compensating
for the lack of address definitions in <gint/mpu/tmu.h>. This
interface is likely to evolve in the future to better integrate the
address in the MPU headers and move them out of the driver.
* Now uses topti instead of fxlib for text (including MMU failure)
* Fit .pretext into 4k for everything before MMU succeeds
* A short version of sprintf() for dynamic messages
* Support a driver function, status(), to allow early driver debug
* Expose more useful platform information in <gint/mpu.h>
* Expose the first of a few CASIOWIN syscalls
