@add

* special fxcg50 dupdate_noint() which display the content of the VRM without using the DMA (usefull for debugging)

@update
* update the drivers interface to get some information about the current running drivers' context
* remove the old cpu_setVBR() function

@fix
* fix cpu_setVBR() returned value
* fix kquit() drivers restore atomic error

include/gint/display-cg.h

@@ -122,6 +122,8 @@ void dsetvram(uint16_t *main, uint16_t *secondary);
    Returns the VRAM buffer addresses used to render on fx-CG 50. */
 void dgetvram(uint16_t **main, uint16_t **secondary);
 
+/* vdupdate_noint(): Push the VRAM to the display driver without DMA */
+extern void dupdate_noint(void);
 #endif /* FXCG50 */
 
 #endif /* GINT_DISPLAY_CG */

include/gint/drivers.h

@@ -123,8 +123,15 @@ typedef struct
 extern void *drivers_context_create(void);
 extern void drivers_context_destroy(void **buffctx);
 extern void drivers_wait(void);
-extern void drivers_save_and_init(void *buffctx);
-extern void drivers_save(void *buffctx);
-extern void drivers_restore(void *buffctx);
-extern void drivers_switch(void *currctx, void *nextctx);
+extern void *drivers_switch(void *buffctx);
+extern void *drivers_restore(void *buffctx);
+extern int drivers_save_and_init(void *buffctx);
+extern int drivers_save(void *buffctx);
+extern int drivers_context_duplicate(void **dst, void *src);
+extern void *drivers_init(void *buffctx);
+extern void *drivers_get_current(void);
+
+// default world
+extern void *kernel_env_casio;
+extern void *kernel_env_gint;
 #endif /* GINT_DRIVERS */

src/cpu/helpers.S

@@ -2,6 +2,7 @@
 **	gint:core:vbr - Assembler-level VBR management
 */
 
+.text
 .global _cpu_setCPUOPM
 .global _cpu_getCPUOPM
 .global _cpu_getSR
@@ -10,51 +11,6 @@
 .global _cpu_getVBR
 
 
-/* cpu_setVBR(): Change VBR address */
-#if 0
-.section .gint.mapped, "ax"
-_cpu_setVBR_reloc:
-	mov.l	r8, @-r15
-	mov.l	r9, @-r15
-	sts.l	pr, @-r15
-
-	/* Block all interrupts by setting IMASK=15 */
-	mov	#0xf, r9
-	shll2	r9
-	shll2	r9
-	stc	sr, r0
-	or	r9, r0
-	ldc	r0, sr
-
-	/* Set the new VBR address */
-	stc	vbr, r8
-	ldc	r4, vbr
-
-	/* Call the configuration function */
-	jsr	@r5
-	mov	r6, r4
-
-	/* Enable interrupts again */
-	stc	sr, r0
-	not	r9, r9
-	and	r9, r0
-	ldc	r0, sr
-
-	/* Return the previous VBR address */
-	mov	r8, r0
-
-	lds.l	@r15+, pr
-	mov.l	@r15+, r9
-	rts
-	mov.l	@r15+, r8
-
-.section .gint.mappedrel, "aw"
-_cpu_setVBR:
-	.long	_cpu_setVBR_reloc
-#endif
-
-.text
-
 /* cpu_setCPUOPM(): Change the CPU Operation Mode register */
 _cpu_setCPUOPM:
 	/* Set CPUOPM as requested */
@@ -100,15 +56,16 @@ _cpu_setVBR:
 	mov	#0xf, r1
 	shll2	r1
 	shll2	r1
-	stc	sr, r0
-	or	r0, r1
+	stc	sr, r2
+	or	r2, r1
 	ldc	r1, sr
 
 	/* switch VBR */
+	stc	vbr, r0
 	ldc	r4, vbr
 
 	/* resotre old SR */
-	ldc	r0, sr
+	ldc	r2, sr
 	rts
 	nop
 

src/kernel/drivers.c

@@ -2,9 +2,10 @@
 //	gint:core:drivers - Drivers manager
 //---
 #include <gint/drivers.h>
-#include <gint/std/stdlib.h>
 #include <gint/hardware.h>
 #include <gint/atomic.h>
+#include <gint/std/string.h>
+#include <gint/std/stdlib.h>
 
 #include "drivers.h"
 
@@ -33,6 +34,21 @@ void *drivers_context_create(void)
 
 }
 
+/* drivers_context_duplicate(): Duplicate an environment */
+int drivers_context_duplicate(void **dst, void *src)
+{
+	if (src == NULL)
+		return (-1);
+	size_t ctxsz = drivers_context_get_size();
+	*dst = realloc(*dst, ctxsz);
+	if (*dst == NULL)
+		return (-2);
+	atomic_begin();
+	memcpy(*dst, src, ctxsz);
+	atomic_end();
+	return (0);
+}
+
 /* drivers_context_destroy(): Destroy generated context */
 void drivers_context_destroy(void **buffctx)
 {
@@ -47,6 +63,8 @@ void drivers_context_destroy(void **buffctx)
 //---
 // Drivers interface
 //---
+/* current env drivers information */
+void *kernel_env_current = NULL;
 
 /* driver_wait(): Wait until all driver have finished */
 void drivers_wait(void)
@@ -57,26 +75,16 @@ void drivers_wait(void)
 	}
 }
 
-/* drivers_save_and_exit(): save the current context and init the next */
-void drivers_save_and_init(void *buffctx)
-{
-	atomic_begin();
-	for driver_asc(drv) {
-		if (isSH3() && drv->driver_sh3 != NULL)
-			drv->driver_sh3();
-		if (drv->ctx_save != NULL)
-			drv->ctx_save(buffctx);
-		if (drv->ctx_size != NULL)
-			buffctx += (drv->ctx_size() + 3) & ~3;
-		if (drv->init != NULL)
-			drv->init();
-	}
-	atomic_end();
-}
-
 /* drivers_save(): save the current drivers' context */
-void drivers_save(void *buffctx)
+int drivers_save(void *buffctx)
 {
+	if (buffctx == NULL)
+		return (-1);
+
+	/* we need to wait until all transction has been done */
+	drivers_wait();
+
+	/* save the current drivers state into the given env */
 	atomic_begin();
 	buffctx += drivers_context_get_size();
 	for driver_dsc(drv) {
@@ -86,12 +94,24 @@ void drivers_save(void *buffctx)
 			drv->ctx_save(buffctx);
 	}
 	atomic_end();
+	return (0);
 }
 
 /* drivers_restore(): restore entier drivers' context */
-void drivers_restore(void *buffctx)
+void *drivers_restore(void *buffctx)
 {
+	void *tmp;
+
+	if (buffctx == NULL)
+		return (NULL);
+
+	/* we need to wait until all transction has been done */
+	drivers_wait();
+
+	/* switch current env then restore the saved drivers' env */
 	atomic_begin();
+	tmp = kernel_env_current;
+	kernel_env_current = buffctx;
 	for driver_asc(drv) {
 		if (drv->ctx_restore != NULL)
 			drv->ctx_restore(buffctx);
@@ -99,12 +119,48 @@ void drivers_restore(void *buffctx)
 			buffctx += (drv->ctx_size() + 3) & ~3;
 	}
 	atomic_end();
+
+	/* return the previous env */
+	return (tmp);
 }
 
-/* drivers_switch(): Switch between two world */
-void drivers_switch(void *currctx, void *nextctx)
+/* drivers_save_and_exit(): save the current context and init the next */
+void *drivers_init(void *buffctx)
 {
-	drivers_wait();
-	drivers_save(currctx);
-	drivers_restore(nextctx);
+	void *tmp;
+
+	if (buffctx == NULL)
+		return (NULL);
+
+	/* switch the current env then initialize it */
+	atomic_begin();
+	tmp = kernel_env_current;
+	kernel_env_current = buffctx;
+	for driver_asc(drv) {
+		if (isSH3() && drv->driver_sh3 != NULL)
+			drv->driver_sh3();
+		if (drv->init != NULL)
+			drv->init();
+	}
+	atomic_end();
+
+	/* return the previous env */
+	return (tmp);
+}
+
+//---
+// abstraction
+//---
+
+/* drivers_switch(): Switch between two world */
+void *drivers_switch(void *buffctx)
+{
+	drivers_save(kernel_env_current);
+	return (drivers_restore(buffctx));
+}
+
+/* drivers_get_current(): return the current context information */
+void *drivers_get_current(void)
+{
+	return (kernel_env_current);
 }

src/kernel/hypervisor.c

@@ -10,21 +10,23 @@
 extern void *kernel_env_casio;
 extern void *kernel_env_gint;
 
+#if 0
 /* gint_switch(): Temporarily switch out of gint */
 GWEAK void gint_switch(void (*function)(void))
 {
-	/* Switch from gint to the OS after a short wait */
-	atomic_begin();
-	drivers_wait();
-	drivers_switch(kernel_env_gint, kernel_env_casio);
-	atomic_end();
+	void *buffctx;
 
-	if(function != NULL)
-		function();
+	/* check useless switch */
+	if(function == NULL)
+		return;
+
+	/* Switch from gint to the OS after a short wait */
+	buffctx = drivers_switch(kernel_env_casio);
+
+	/* involve function */
+	function();
 
 	/* Then switch back to gint once the OS finishes working */
-	atomic_begin();
-	drivers_wait();
-	drivers_switch(kernel_env_casio, kernel_env_gint);
-	atomic_end();
+	drivers_switch(buffctx);
 }
+#endif

src/kernel/kernel.c

@@ -31,17 +31,16 @@ void kinit(void)
 	/* create Casio's context, switch to Gint and save Gint context */
 	kernel_env_gint = drivers_context_create();
 	kernel_env_casio = drivers_context_create();
-	drivers_wait();
-	drivers_save_and_init(kernel_env_casio);
+	drivers_save(kernel_env_casio);
+	drivers_init(kernel_env_gint);
 	drivers_save(kernel_env_gint);
 }
 
 /* kquit(): Quit gint and give back control to the system */
 void kquit(void)
 {
-	drivers_wait();
-	atomic_begin();
 	drivers_restore(kernel_env_casio);
+	atomic_begin();
 	drivers_context_destroy(&kernel_env_casio);
 	drivers_context_destroy(&kernel_env_gint);
 	atomic_end();

src/render-cg/dupdate.c

@@ -11,3 +11,9 @@ void dupdate(void)
 	   overwriting the data which is about to be sent. */
 	dvram_switch();
 }
+
+/* dupdate_noint(): Push the video RAM to the display driver without DMA */
+void dupdate_noint(void)
+{
+	r61524_display(gint_vram, 0, 224, R61524_CPU);
+}