[fw-isoldr] Introduced GPIO support for reset button handling.

Author: DC-SWAT

firmware/isoldr/loader/include/gpio.h

@@ -0,0 +1,53 @@
+/**
+ * DreamShell ISO Loader
+ * SH4 GPIO
+ * (c)2025 SWAT <http://www.dc-swat.ru>
+ */
+#ifndef __GPIO_H__
+#define __GPIO_H__
+
+#include <main.h>
+#include <exception.h>
+#include <kos/regfield.h>
+
+/* GPIO registers */
+#define PCTRA   (*(volatile unsigned int *)0xFF80002C)
+#define PDTRA   (*(volatile unsigned short *)0xFF800030)
+#define GPIOIC  (*(volatile unsigned int *)0xFFD8001C)
+
+/* Bit positions in PCTRA */
+#define GPIO_PIN_POS(pin)    (pin * 2)
+
+/* Bit masks for PCTRA */
+#define GPIO_PIN_MASK(pin)    GENMASK(GPIO_PIN_POS(pin) + 1, GPIO_PIN_POS(pin))  /* 2 bits */
+#define GPIO_PIN_CFG_IN       0  /* Configure as input */
+#define GPIO_PIN_CFG_OUT(pin) BIT(GPIO_PIN_POS(pin)) /* Configure as output (01b) */
+
+static inline void gpio_set_as_input(int pin) {
+    PCTRA = (PCTRA & ~GPIO_PIN_MASK(pin)) | GPIO_PIN_CFG_IN;
+}
+
+static inline void gpio_set_as_output(int pin) {
+    PCTRA = (PCTRA & ~GPIO_PIN_MASK(pin)) | GPIO_PIN_CFG_OUT(pin);
+}
+
+static inline int gpio_read_pin(int pin) {
+    return (PDTRA >> pin) & 1;
+}
+
+static inline void gpio_write_pin(int pin, int value) {
+    if (value)
+        PDTRA |= BIT(pin);
+    else
+        PDTRA &= ~BIT(pin);
+}
+
+static inline void gpio_enable_interrupt(int pin) {
+    GPIOIC |= BIT(pin);
+}
+
+static inline void gpio_disable_interrupt(int pin) {
+    GPIOIC &= ~BIT(pin);
+}
+
+#endif /* __GPIO_H__ */

firmware/isoldr/loader/include/main.h

@@ -68,6 +68,8 @@
 #define HOLLY_REV_VA0 0x0b
 #define holly_revision() (*(vuint32 *)NONCACHED_ADDR(0x005f689c))
 
+#define GPIO_PIN_RESET_BUTTON 0
+
 extern isoldr_info_t *IsoInfo;
 extern uint32 loader_size;
 extern uint32 loader_addr;

firmware/isoldr/loader/include/syscalls.h

@@ -222,4 +222,6 @@ void restore_syscalls(void);
 
 int sys_misc_init(void);
 
+void menu_exit(void);
+
 #endif

firmware/isoldr/loader/syscalls.c

@@ -11,6 +11,7 @@
 #include <mmu.h>
 #include <cdda.h>
 #include <maple.h>
+#include <gpio.h>
 #include <arch/cache.h>
 #include <arch/timer.h>
 #include <arch/gdb.h>
@@ -869,6 +870,10 @@ void gdcMainLoop(void) {
 		}
 #endif
 
+		if(gpio_read_pin(GPIO_PIN_RESET_BUTTON) == 0) {
+			menu_exit();
+		}
+
 		if(GDS->status == CMD_STAT_PROCESSING) {
 #ifdef HAVE_MULTI_DISC
 			if (GDS->need_reinit == 1 && GDS->cmd != CMD_INIT) {
@@ -1052,6 +1057,10 @@ int gdcGetDrvStat(uint32 *status) {
 	}
 #endif
 
+	if(gpio_read_pin(GPIO_PIN_RESET_BUTTON) == 0) {
+		menu_exit();
+	}
+
 	if(lock_gdsys()) {
 		DBGFF("Busy\n");
 		return CMD_STAT_BUSY;
@@ -1141,6 +1150,8 @@ void gdcInitSystem(void) {
 	}
 #endif
 
+    gpio_set_as_input(GPIO_PIN_RESET_BUTTON);
+
 	reset_GDS(GDS);
 	gdcMainLoop();
 }
@@ -1392,6 +1403,7 @@ void gdcDummy(int gd_chn, int *arg2) {
 void menu_exit(void) {
 	LOGFF(NULL);
 
+	do {} while(pre_read_xfer_busy());
 	fs_enable_dma(FS_DMA_DISABLED);
 	shutdown_machine();
 

firmware/isoldr/loader/utils.c

@@ -73,12 +73,13 @@ void setup_machine(void) {
 
 void shutdown_machine(void) {
 
+	/* FIXME
 	const uint32 reset_regs[] = {
 		0xa05f6808, 0xa05f6820, 0xa05f6c14, 0xa05f7414, 
 		0xa05f7814, 0xa05f7834, 0xa05f7854, 0xa05f7874, 
 		0xa05f7c14, 0xffa0001c, 0xffa0002c, 0xffa0003c
 	};
-
+	*/
 	irq_disable();
 
 	*(vuint32 *)(0xff000010) = 0;
@@ -104,7 +105,7 @@ void shutdown_machine(void) {
 	addr2 += *(vuint32 *)(addr1);
 
 	*(vuint32 *)(0xa05f8044) = (*(vuint32 *)(0xa05f8044) & 0xfffffffe);
-
+/*
 	for (uint32 i = 0; i < ((sizeof(reset_regs)) >> 2); ++i) {
 		*(vuint32 *)(reset_regs[i]) = (*(vuint32 *)(reset_regs[i]) & 0xfffffffe);
 		for (uint32 j = 0; j < 127; ++j) {
@@ -113,6 +114,7 @@ void shutdown_machine(void) {
 			}
 		}
 	}
+*/
 }
 
 uint Load_BootBin() {