From cfe4f01e3081e20da640f5bfdc6f1d7814bc3e9c Mon Sep 17 00:00:00 2001
From: Mateusz Faderewski <sc@mateuszfaderewski.pl>
Date: Wed, 6 Dec 2023 12:57:01 +0100
Subject: [PATCH] Changed boot type to cold + RI/RDRAM reset (should improve
 game compatibility)

---
 libdragon          |  2 +-
 src/boot/boot.c    | 19 +++++++++++++++----
 src/boot/boot.h    |  1 -
 src/boot/boot_io.h | 22 ----------------------
 src/boot/reboot.S  | 24 +++++++++++++++++++-----
 src/menu/menu.c    |  2 +-
 6 files changed, 36 insertions(+), 34 deletions(-)

diff --git a/libdragon b/libdragon
index 4b38fd56..e6adc203 160000
--- a/libdragon
+++ b/libdragon
@@ -1 +1 @@
-Subproject commit 4b38fd5618007e7ed9040107d0f7e52f2de81a22
+Subproject commit e6adc2034376158ecb47e7498220336ede442ee9
diff --git a/src/boot/boot.c b/src/boot/boot.c
index b4b066ee..d9d2eca3 100644
--- a/src/boot/boot.c
+++ b/src/boot/boot.c
@@ -37,15 +37,26 @@ static void boot_detect_cic_seed (boot_params_t *params) {
 
 void boot (boot_params_t *params) {
     if (params->tv_type == BOOT_TV_TYPE_PASSTHROUGH) {
-        params->tv_type = OS_INFO->tv_type;
+        switch (get_tv_type()) {
+            case TV_PAL:
+                params->tv_type = BOOT_TV_TYPE_PAL;
+                break;
+            case TV_NTSC:
+                params->tv_type = BOOT_TV_TYPE_NTSC;
+                break;
+            case TV_MPAL:
+                params->tv_type = BOOT_TV_TYPE_MPAL;
+                break;
+            default:
+                params->tv_type = BOOT_TV_TYPE_NTSC;
+                break;
+        }
     }
 
     if (params->detect_cic_seed) {
         boot_detect_cic_seed(params);
     }
 
-    OS_INFO->mem_size_6105 = OS_INFO->mem_size;
-
     C0_WRITE_STATUS(C0_STATUS_CU1 | C0_STATUS_CU0 | C0_STATUS_FR);
 
     while (!(cpu_io_read(&SP->SR) & SP_SR_HALT));
@@ -120,7 +131,7 @@ void boot (boot_params_t *params) {
 
     boot_device = (params->device_type & 0x01);
     tv_type = (params->tv_type & 0x03);
-    reset_type = BOOT_RESET_TYPE_NMI;
+    reset_type = BOOT_RESET_TYPE_COLD;
     cic_seed = (params->cic_seed & 0xFF);
     version = (params->tv_type == BOOT_TV_TYPE_PAL) ? 6
             : (params->tv_type == BOOT_TV_TYPE_NTSC) ? 1
diff --git a/src/boot/boot.h b/src/boot/boot.h
index 61ff6546..0bbd910d 100644
--- a/src/boot/boot.h
+++ b/src/boot/boot.h
@@ -41,7 +41,6 @@ typedef struct {
 } boot_params_t;
 
 
-bool boot_is_warm (void);
 void boot (boot_params_t *params);
 
 
diff --git a/src/boot/boot_io.h b/src/boot/boot_io.h
index a251cd9b..6923e4df 100644
--- a/src/boot/boot_io.h
+++ b/src/boot/boot_io.h
@@ -241,28 +241,6 @@ typedef struct {
 #define ROM_CART_BASE               (0x10000000UL)
 #define ROM_CART                    ((io32_t *) ROM_CART_BASE)
 
-/** @brief OS Information Structure. */
-typedef struct {
-    uint32_t tv_type;
-    uint32_t device_type;
-    uint32_t device_base;
-    uint32_t reset_type;
-    uint32_t cic_id;
-    uint32_t version;
-    uint32_t mem_size;
-    uint8_t app_nmi_buffer[64];
-    uint32_t __reserved_1[37];
-    uint32_t mem_size_6105;
-} os_info_t;
-
-#define OS_INFO_BASE                (0x80000300UL)
-#define OS_INFO                     ((os_info_t *) OS_INFO_BASE)
-
-/** @brief The Console was powered on using the power switch. */
-#define OS_INFO_RESET_TYPE_COLD     (0)
-/** @brief The Console was reset using the reset button. */
-#define OS_INFO_RESET_TYPE_NMI      (1)
-
 
 static inline uint32_t cpu_io_read (io32_t *address) {
     io32_t *uncached = UNCACHED(address);
diff --git a/src/boot/reboot.S b/src/boot/reboot.S
index e64a46f1..5d0ab6de 100644
--- a/src/boot/reboot.S
+++ b/src/boot/reboot.S
@@ -2,10 +2,15 @@
 #define REBOOT_ADDRESS      0xA4001000
 #define STACK_ADDRESS       0xA4001FF0
 
+#define RI_ADDRESS          0xA4700000
+
+#define RI_SELECT           0x0C
+#define RI_REFRESH          0x10
+
 
 .set noat
 .section .text.reboot, "ax", %progbits
-.type reboot, %object
+
 reboot_start:
     .global reboot_start
 
@@ -29,6 +34,15 @@ reboot_entry:
 
     li $sp, STACK_ADDRESS
 
+reset_rdram:
+    bnez $s5, reset_rdram_skip
+
+    li $t0, RI_ADDRESS
+
+    sw $zero, RI_REFRESH($t0)
+    sw $zero, RI_SELECT($t0)
+reset_rdram_skip:
+
 detect_console_region:
     li $t0, 1
     beq $s4, $zero, pal_console
@@ -37,16 +51,16 @@ detect_console_region:
 
 pal_console:
     li $ra, 0xA4001554
-    b reset_registers
+    b prepare_registers
 
 ntsc_console:
     li $ra, 0xA4001550
-    b reset_registers
+    b prepare_registers
 
 mpal_console:
     li $ra, 0xA4001554
 
-reset_registers:
+prepare_registers:
     move $at, $zero
     move $v0, $zero
     move $v1, $zero
@@ -56,7 +70,7 @@ reset_registers:
     move $a3, $zero
     move $t0, $zero
     move $t1, $zero
-    move $t2, $zero
+    li $t2, 0x40
     move $t4, $zero
     move $t5, $zero
     move $t6, $zero
diff --git a/src/menu/menu.c b/src/menu/menu.c
index a573bcdb..482f2d0f 100644
--- a/src/menu/menu.c
+++ b/src/menu/menu.c
@@ -157,7 +157,7 @@ static struct views_s {
 void menu_run (boot_params_t *boot_params) {
     menu_init(boot_params);
 
-    while (exception_reset_time() < RESET_TIME_LENGTH) {
+    while (exception_reset_time() == 0) {
         surface_t *display = (frame_counter >= FRAMERATE_DIVIDER) ? display_try_get() : NULL;
 
         if (display != NULL) {