gint/include/gint/gint.h
redoste 76c82beec6
intc: allow user-space handlers to access the interrupted context
This workaround using a gint_call_t with an odd address is not realy the
cleanest idea but it helps keep the existing intc_generic_handler in
the 32 bytes size limit of the VBR space.
2023-05-27 18:36:15 +02:00

155 lines
6 KiB
C

//---
// gint - An alternative runtime environment for fx9860g and fxcg50
//---
#ifndef GINT_GINT
#define GINT_GINT
#ifdef __cplusplus
extern "C" {
#endif
#include <gint/defs/types.h>
#include <gint/defs/call.h>
#include <gint/config.h>
#include <gint/intc.h>
/* gint_world_switch(): Switch out of gint to execute a function
This function can be used to leave gint, restore the OS's hardware state,
and execute code there before returning to gint. By doing this one can
effectively interleave gint with the standard OS execution. gint drivers
will be inactive during this time but OS features such as BFile or the
main menu are available.
This main uses for this switch are going back to the main menu and using
BFile function. You can go back to the main menu easily by calling getkey()
(or getkey_opt() with the GETKEY_MENU flag set) and pressing the MENU key,
or by calling gint_osmenu() below which uses this switch.
The code to execute while in OS mode is passed as a gint call; you can use
GINT_CALL() to create one. This allows you to pass arguments to your
function, as well as return an int.
@function A GINT_CALL() to execute while in OS mode
-> Returns the return value of (function), if any, 0 if function is NULL. */
int gint_world_switch(gint_call_t function);
/* This function is an older version of gint_world_switch() which only accepts
functions with no arguments and no return value. It will be removed in
gint 3. */
__attribute__((deprecated("Use gint_world_switch() instead")))
void gint_switch(void (*function)(void));
/* gint_world_sync(): Synchronize asynchronous drivers
This function waits for asynchronous tasks to complete by unbinding all
drivers. This is useful in certain hardware operations while remaining in
gint. */
void gint_world_sync(void);
/* gint_osmenu(): Call the calculator's main menu
This function safely invokes the calculator's main menu with gint_switch().
If the user selects the gint application again in the menu, this function
reloads gint and returns. Otherwise, the add-in is fully unloaded by the
system and the application terminates.
This function is typically called when the [MENU] key is pressed during a
call to getkey(), but can also be called manually. */
void gint_osmenu(void);
/* gint_osmenu_native(): Like gint_osmenu() without the world switch
This is a replacement for gint_osmenu() which can be used when the current
kernel is already the native OS kernel. */
void gint_osmenu_native(void);
/* gint_setrestart(): Set whether to restart the add-in after exiting
An add-in that returns from its main() function automatically exits to the
OS' main menu. However, when this happens the OS does not allow the add-in
to be restarted unless another add-in is launched first. (This is because
the OS tries to *resume* the current add-in, which then proceeds to exit
again immediately.)
This function enables a gint trick where after main() returns the add-in
will invoke the main menu with gint_osmenu() rather than exiting. If the
add-in is selected again, gint will jump back to the entry point, creating
the illusion that the add-in exited and was then restarted.
@restart 0 to exit, 1 to restart by using gint_osmenu() */
void gint_setrestart(int restart);
/* This function has been moved to the INTC driver */
__attribute__((deprecated("Use intc_handler() instead")))
static GINLINE void *gint_inthandler(int code, void const *h, size_t size) {
return intc_handler(code, h, size);
}
/* gint_inth_callback(): Callback from interrupt handler to userland
This function performs an indirect call as with gint_call(), afters saving
the user context, enabling interrupts and going to user bank. This is useful
to call user code from interrupt handlers. You can think of it as a kernel-
space escape to virtualized userland during interrupt handling.
This function can only be useful in an interrupt handler's assembler code.
It is loaded at a runtime-determined address and accessed through a function
pointer, like this:
mov.l .callback, r0
mov.l @r0, r0 # because function pointer
mov <address of gint_call_t object>, r4
jsr @r0
nop
.callback:
.long _gint_inth_callback
The gint_call_t object can be built with GINT_CALL_FLAG to specify that the
called function should get a pointer to a gint_inth_callback_context_t
strcture as its first argument.
@call Address of a gint_call_t object
Returns the return value of the callback. */
extern int (*gint_inth_callback)(gint_call_t const *call);
/* gint_inth_callback_context_t: Context of the interrupted function when an
interrupt is handled by gint_inth_callback. */
typedef struct {
uint32_t ssr;
uint32_t spc;
uint32_t r7;
uint32_t r6;
uint32_t r5;
uint32_t r4;
uint32_t r3;
uint32_t r2;
uint32_t r1;
uint32_t r0;
} gint_inth_callback_context_t;
/* gint_set_quit_handler(): Setup a call to be invoked when leaving the add-in
This function sets up the provided GINT_CALL() to be invoked when the
add-in is unloaded, which is either when we exit from main() or when
starting another application from the main menu. Crucially, this is only
*after* selecting an application, not before opening the main menu. The
quit handler is not invoked if the user re-enters the add-in.
This is based on the SetQuitHandler() syscall, and therefore the callback
runs in the OS world by default. If [run_in_os_world] is set to false, a
world switch will be performed to run the callback in the gint world.
TODO: Currently the quit handler is not called when exiting from main().
TODO: Detail how this interacts with destructor functions!
TODO: [run_in_os_world == false] is not honored yet (because unstable)
@call Callback to be performed when leaving add-in
@run_in_os_world true to stay in OS world, false to use gint world */
void gint_set_quit_handler(gint_call_t gcall, bool run_in_os_world);
#ifdef __cplusplus
}
#endif
#endif /* GINT_GINT */