Commit Graph

29 Commits

Author SHA1 Message Date
Lephe 42081c9968
intc: allow any call in intc_handler_function() 2021-05-12 09:17:24 +02:00
Lephe c37f150600
use GINT_CALL() in every API that has callbacks
* 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"
2021-04-27 14:29:38 +02:00
Lephe c9264a06d5
kernel: driver and world system overhaul
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.
2021-04-23 20:44:08 +02:00
Lephe 6440527527
rtc: add an rtc_ticks() function similar to RTC_GetTicks() 2021-02-02 18:19:08 +01:00
Lephe e5abe03b89
kernel: dynamic loading of GMAPPED functions to user RAM
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.
2020-09-17 14:48:54 +02:00
Lephe 0622928f22
rtc: robust interrupt handling and SH3 compatibility
This commit changes the interrupt handler arrangement to support the PRI
interrupt on SH3 (a gap is needed between 0xaa0 and its helper).

It also introduces the use of the _gint_inth_callback function for the
callback, which provides dynamic TLB during the interrupt, and revealed
a bug about IMASK not being set automatically on SH3.

Finally, it sets the interrupt settings of the RTC more conservatively,
by wiping RCR1 and the carry, alarm and periodic interrupt flags during
initialization and context restoration.
2020-07-19 20:06:50 +02:00
Lephe 5cac2cf7fc
rtc: take input similar to timer_setup() in rtc_timer_start() 2020-07-16 17:27:56 +02:00
Lephe 2751dcf045
remove the .gint.data section
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.
2020-07-10 16:36:05 +02:00
Lephe a91a0a483b
core: remove some useless hardware info 2020-06-20 19:23:50 +02:00
Lephe 1c7b1350b4
general cleanup of the kernel
* 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.
2020-06-20 17:18:51 +02:00
Lephe 85311a0b31
drivers: update the model, replacing unload() with wait()
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.
2020-05-10 16:36:21 +02:00
Lephe 4485e7f865
core, tmu: add gint_switch(), return to menu, and improve timer code
* 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.
2020-05-10 14:03:41 +02:00
Lephe 2cdf925f94
interrupts: save caller-saved registers in main handler
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.
2020-05-06 20:45:35 +02:00
Lephe 61da7debc8
code review and display driver changes
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]
2020-02-23 16:05:25 +01:00
Lephe 61e68d01bb
expose more platform-agnostic code
May be useful later on for libraries such as libprof.
2019-09-06 12:16:31 +02:00
lephe 3324d58afa core: add a hardware detection interface 2019-07-04 12:11:43 -04:00
lephe 04231ea5d6 dma: add a new driver to support r61524
Also add a power interface (without driving code) and switch toolchain
because the previous sh4eb-nofpu-elf toolchain was not completely
FPU-free.
2019-03-10 15:45:34 +01:00
lephe 3f7c0a04ad way too much, including bopti/topti, timers, and more. 2019-02-21 21:00:26 +01:00
lephe 298338f633 More timers, RTC, basic overclock-resistant keyboard, CPG, PFC, driver levels. 2018-08-19 17:11:37 +02:00
lephe c50cbf6a9c Make room for an fx-cg50 compatible version. Enhanced build system. 2018-04-09 08:31:12 +02:00
lephe 5e66efc560 Interrupt controller module description (WIP), task switch and return to menu. 2017-07-01 16:07:14 +02:00
lephe 57a7e1c2d4 More quality review, more registers saved at startup. 2017-04-13 21:59:13 +02:00
lephe 31e2b453dd Redesigned timer module: got a possibly infinite amount of virtual timers. 2017-03-01 11:07:28 +01:00
lephe d852bc3310 Huh... debug app for crashes & whole new interrupt system. Minor edits. 2017-02-25 19:02:07 +01:00
lephe 98fdbbc333 Proper RTC callback system. Moved keyboard to RTC (saves a timer). Reduced use of 7705.h / 7305.h. 2016-09-04 11:35:41 +02:00
lephe 58db663ae6 Some time manipulation. Added the targets to the .gitignore file. 2016-08-08 15:01:33 +02:00
lephe 1f223f807f Added an RTC test (clock), image part drawing and a few standard functions (stdlib, time). 2016-08-02 07:51:44 +02:00
lephe b2151886bc Added formatted printing for stdio: handles everything except doubles and %m. 2016-07-25 22:38:47 +02:00
lephe 7f174043a5 Reported TLB issues. Moved internal headers files, added rtc module and alloca. 2016-07-25 09:04:22 +02:00