From a9ef7af3b1319643e853e9909a5b5c4c30089edc Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Mon, 10 Jan 2022 13:55:13 -0800
Subject: [PATCH] GBA BIOS: Change fix for #1059 to break fewer games

---
 src/gba/bios.c     |  2 +-
 src/gba/hle-bios.c | 18 +++++++++---------
 src/gba/hle-bios.s | 38 +++++++++++++++++++-------------------
 3 files changed, 29 insertions(+), 29 deletions(-)

diff --git a/src/gba/bios.c b/src/gba/bios.c
index 171b09ec9..05782c39d 100644
--- a/src/gba/bios.c
+++ b/src/gba/bios.c
@@ -428,7 +428,7 @@ void GBASwi16(struct ARMCore* cpu, int immediate) {
 
 	switch (immediate) {
 	case 0xF0: // Used for internal stall counting
-		cpu->gprs[12] = gba->biosStall;
+		cpu->gprs[11] = gba->biosStall;
 		return;
 	case 0xFA:
 		GBAPrintFlush(gba);
diff --git a/src/gba/hle-bios.c b/src/gba/hle-bios.c
index 9ee6dd5b1..da4e07111 100644
--- a/src/gba/hle-bios.c
+++ b/src/gba/hle-bios.c
@@ -9,17 +9,17 @@ const uint8_t hleBios[SIZE_BIOS] = {
 	0x03, 0x10, 0xd0, 0xe5, 0xea, 0x00, 0x51, 0xe3, 0x4c, 0x01, 0x9f, 0x15,
 	0x10, 0xff, 0x2f, 0xe1, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf0, 0x29, 0xe1,
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5d, 0xe3, 0x01, 0xd3, 0xa0, 0x03,
-	0x20, 0xd0, 0x4d, 0x02, 0x10, 0x50, 0x2d, 0xe9, 0x02, 0x40, 0x5e, 0xe5,
-	0xd4, 0xc0, 0xa0, 0xe3, 0x04, 0x41, 0x9c, 0xe7, 0xd2, 0xcf, 0xa0, 0xe3,
-	0x04, 0x00, 0x5c, 0xe1, 0x00, 0xc0, 0x4f, 0xe1, 0x00, 0x10, 0x2d, 0xe9,
-	0x80, 0xc0, 0x0c, 0xe2, 0x1f, 0xc0, 0x8c, 0xe3, 0x0c, 0xf0, 0x21, 0xe1,
-	0x00, 0x00, 0xf0, 0x0f, 0x04, 0x40, 0x2d, 0xe9, 0x00, 0x00, 0x54, 0xe3,
+	0x20, 0xd0, 0x4d, 0x02, 0x00, 0x58, 0x2d, 0xe9, 0x02, 0xc0, 0x5e, 0xe5,
+	0xd4, 0xb0, 0xa0, 0xe3, 0x0c, 0xc1, 0x9b, 0xe7, 0xd2, 0xbf, 0xa0, 0xe3,
+	0x0c, 0x00, 0x5b, 0xe1, 0x00, 0xb0, 0x4f, 0xe1, 0x00, 0x08, 0x2d, 0xe9,
+	0x80, 0xb0, 0x0b, 0xe2, 0x1f, 0xb0, 0x8b, 0xe3, 0x0b, 0xf0, 0x21, 0xe1,
+	0x00, 0x00, 0xf0, 0x0f, 0x04, 0x40, 0x2d, 0xe9, 0x00, 0x00, 0x5c, 0xe3,
 	0x00, 0x00, 0xa0, 0xe1, 0x00, 0x00, 0xa0, 0xe1, 0x00, 0x00, 0xa0, 0xe1,
 	0x00, 0x00, 0xa0, 0xe1, 0x00, 0x00, 0xa0, 0xe1, 0x00, 0x00, 0xa0, 0xe1,
-	0x0f, 0xe0, 0xa0, 0xe1, 0x14, 0xff, 0x2f, 0x11, 0x00, 0x00, 0xa0, 0xe1,
+	0x0f, 0xe0, 0xa0, 0x11, 0x1c, 0xff, 0x2f, 0x11, 0x00, 0x00, 0xa0, 0xe1,
 	0x00, 0x00, 0xa0, 0xe1, 0x00, 0x00, 0xa0, 0xe1, 0x04, 0x40, 0xbd, 0xe8,
-	0x93, 0xf0, 0x29, 0xe3, 0x00, 0x10, 0xbd, 0xe8, 0x0c, 0xf0, 0x69, 0xe1,
-	0x10, 0x50, 0xbd, 0xe8, 0x0e, 0xf0, 0xb0, 0xe1, 0x00, 0x00, 0x00, 0x00,
+	0x93, 0xf0, 0x29, 0xe3, 0x00, 0x08, 0xbd, 0xe8, 0x0b, 0xf0, 0x69, 0xe1,
+	0x00, 0x58, 0xbd, 0xe8, 0x0e, 0xf0, 0xb0, 0xe1, 0x00, 0x00, 0x00, 0x00,
 	0x04, 0x20, 0xa0, 0xe3, 0x00, 0x00, 0x00, 0x00, 0xb0, 0x01, 0x00, 0x00,
 	0xb0, 0x01, 0x00, 0x00, 0xb4, 0x01, 0x00, 0x00, 0xb0, 0x01, 0x00, 0x00,
 	0xcc, 0x01, 0x00, 0x00, 0xc4, 0x01, 0x00, 0x00, 0x48, 0x03, 0x00, 0x00,
@@ -73,5 +73,5 @@ const uint8_t hleBios[SIZE_BIOS] = {
 	0x01, 0xa0, 0xa0, 0xe1, 0xfa, 0x07, 0xa0, 0xe8, 0xfa, 0x07, 0xa0, 0xe8,
 	0xfa, 0x07, 0xa0, 0xe8, 0xfa, 0x07, 0xa0, 0xe8, 0x00, 0x10, 0xa0, 0xe3,
 	0xf0, 0x07, 0xbd, 0xe8, 0x1e, 0xff, 0x2f, 0xe1, 0xb0, 0x01, 0x00, 0x00,
-	0x04, 0xc0, 0x5c, 0xe2, 0xfd, 0xff, 0xff, 0x8a, 0x1e, 0xff, 0x2f, 0xe1
+	0x04, 0xb0, 0x5b, 0xe2, 0xfd, 0xff, 0xff, 0x8a, 0x1e, 0xff, 0x2f, 0xe1
 };
diff --git a/src/gba/hle-bios.s b/src/gba/hle-bios.s
index be0d81703..52d5c88dc 100644
--- a/src/gba/hle-bios.s
+++ b/src/gba/hle-bios.s
@@ -31,36 +31,36 @@ swiBase:
 cmp    sp, #0
 moveq  sp, #0x04000000
 subeq  sp, #0x20
-stmfd  sp!, {r4, r12, lr}
-ldrb   r4, [lr, #-2]
-mov    r12, #swiTable
-ldr    r4, [r12, r4, lsl #2]
-mov    r12, #StallCall
-cmp    r12, r4
-mrs    r12, spsr
-stmfd  sp!, {r12}
-and    r12, #0x80
-orr    r12, #0x1F
-msr    cpsr_c, r12
-swieq  0xF00000  @ Special mGBA-internal call to load the stall count into r12
+stmfd  sp!, {r11, r12, lr}
+ldrb   r12, [lr, #-2]
+mov    r11, #swiTable
+ldr    r12, [r11, r12, lsl #2]
+mov    r11, #StallCall
+cmp    r11, r12
+mrs    r11, spsr
+stmfd  sp!, {r11}
+and    r11, #0x80
+orr    r11, #0x1F
+msr    cpsr_c, r11
+swieq  0xF00000  @ Special mGBA-internal call to load the stall count into r11
 stmfd  sp!, {r2, lr}
-cmp    r4, #0
+cmp    r12, #0
 nop
 nop
 nop
 nop
 nop
 nop
-mov    lr, pc
-bxne   r4
+movne  lr, pc
+bxne   r12
 nop
 nop
 nop
 ldmfd  sp!, {r2, lr}
 msr    cpsr, #0x93
-ldmfd  sp!, {r12}
-msr    spsr, r12
-ldmfd  sp!, {r4, r12, lr}
+ldmfd  sp!, {r11}
+msr    spsr, r11
+ldmfd  sp!, {r11, r12, lr}
 movs   pc, lr
 .word 0
 .word 0xE3A02004
@@ -310,6 +310,6 @@ ArcTan:
 ArcTan2:
 
 StallCall:
-subs r12, #4
+subs r11, #4
 bhi StallCall
 bx lr