inputredirection hook in ir:user cpp emulation => c-stick works in games now, also hook refactoring

sysmodules/rosalina/source/input_redirection.c

@@ -239,24 +239,33 @@ Result InputRedirection_DoOrUndoPatches(void)
         if(R_SUCCEEDED(res))
         {
             static u32 irOrigReadingCode[5] = {
-                 0xE5940000, // ldr r0, [r4]
-                 0xE1A01005, // mov r1, r5
-                 0xE3A03005, // mov r3, #5
-                 0xE3A02011, // mov r2, #17
+                0xE5940000, // ldr r0, [r4]
+                0xE1A01005, // mov r1, r5
+                0xE3A03005, // mov r3, #5
+                0xE3A02011, // mov r2, #17
+                0x00000000  // (bl i2c_read_raw goes here)
             };
 
             static const u32 irOrigWaitSyncCode[] = {
                 0xEF000024, // svc 0x24 (WaitSynchronization)
-                0xE1B01FA0, // movs r1, r0,lsr#31
+                0xE1B01FA0, // movs r1, r0, lsr#31
                 0xE1A0A000, // mov r10, r0
             };
 
-            static u32 *irHookLoc, *irWaitSyncLoc;
+            static const u32 irOrigCppFlagCode[] = {
+                0xE3550000, // cmp r5, #0
+                0xE3A0B080, // mov r11, #0x80
+                0xE28D0060, // add r0, sp, #0xb0+var_50
+                0x0A00002C // beq loc_105688
+            };
+
+            static u32 *irHookLoc, *irWaitSyncLoc, *irCppFlagLoc;
 
             if(inputRedirectionEnabled)
             {
                 memcpy(irHookLoc, &irOrigReadingCode, sizeof(irOrigReadingCode));
                 memcpy(irWaitSyncLoc, &irOrigWaitSyncCode, sizeof(irOrigWaitSyncCode));
+                memcpy(irCppFlagLoc, &irOrigCppFlagCode, sizeof(irOrigCppFlagCode));
             }
             else
             {
@@ -264,10 +273,10 @@ Result InputRedirection_DoOrUndoPatches(void)
                 u32 irCodePhys = (u32)PA_FROM_VA_PTR(&irCodePatchFunc);
 
                 u32 irHook[] = {
-                    0xE59F0004, // ldr r0,  [pc, #4]
-                    0xE59FC004, // ldr r12, [pc, #4]
-                    0xE12FFF1C, // bx  r12
-                    irDataPhys,
+                    0xE5940000, // ldr r0, [r4]
+                    0xE1A01005, // mov r1, r5
+                    0xE59FC000, // ldr r12, [pc] (actually +8)
+                    0xE12FFF3C, // blx r12
                     irCodePhys,
                 };
 
@@ -285,17 +294,29 @@ Result InputRedirection_DoOrUndoPatches(void)
                     return -5;
                 }
 
-                *(void **)(irCodePhys + 4) = decodeARMBranch(off + 4);
+                u32 *off3 = (u32 *)memsearch((u8 *)0x00100000, &irOrigCppFlagCode, totalSize, sizeof(irOrigCppFlagCode));
+                if(off3 == NULL)
+                {
+                    svcUnmapProcessMemoryEx(processHandle, 0x00100000, totalSize);
+                    return -6;
+                }
+
+                *(void **)(irCodePhys + 8) = decodeARMBranch(off + 4);
+                *(void **)(irCodePhys + 12) = (void*)irDataPhys;
 
                 irHookLoc = off;
                 irWaitSyncLoc = off2;
+                irCppFlagLoc = off3;
+
+                irOrigReadingCode[4] = off[4]; // Copy the branch.
 
-                irOrigReadingCode[4] = off[4];
                 memcpy(irHookLoc, &irHook, sizeof(irHook));
 
                 // This "NOP"s out a WaitSynchronisation1 (on the event bound to the 'IR' interrupt)
                 *irWaitSyncLoc = 0xE3A00000; // mov r0, #0
-                memcpy((u32*)irHookLoc, irHook, sizeof(irHook));
+
+                // This NOPs out a flag check in ir:user's CPP emulation
+                *(irCppFlagLoc+3) = 0xea00002c;
             }
         }
 

sysmodules/rosalina/source/input_redirection_hooks.s

@@ -102,20 +102,21 @@ pop {r4-r6, pc}
 .global irCodePatchFunc
 .type   irCodePatchFunc, %function
 irCodePatchFunc:
+add lr, lr, #4 @ Skip the address in the hook when we return to the original function
 b skip_vars
 
 i2c_readdeviceraw_addr:
     .word 0
+redirected_input_addr:
+	.word 0
 
 skip_vars:
-
-@ Address to read from is passed by the hook, save it.
-mov r6, r0
-
+stmfd sp!, {r4-r5, lr}
 ir_check_i2c:
 @ Original code. Does an i2c read at device 17 func 5.
-ldr r0, [r4]
-mov r1, r5
+@ r0 and r1 were set up by the hook
+
+mov r4, r1                  @ save r1
 mov r2, #17
 mov r3, #5
 
@@ -123,18 +124,21 @@ adr r12, i2c_readdeviceraw_addr
 ldr r12, [r12]
 blx r12
 
+adr r5, redirected_input_addr
+ldr r5, [r5]
+
 ldr r1, =0x80800081         @ no c-stick activity / zlzr not pressed
 cmp r0, #0                  @ check if the i2c read succeeded completely
 
-ldreq r2, [r5]
+ldreq r2, [r4]
 tsteq r2, #0x100            @ apparently this is set only if the c-stick hasn't been moved yet
 movne r2, r1
 
 cmp r1, r2
-ldreq r0, [r6]              @ Pull the remote input in.
-streq r0, [r5]              @ store it instead of the value read from i2c
+ldreq r0, [r5]              @ Pull the remote input in.
+streq r0, [r4]              @ store it instead of the value read from i2c
 
 @ Return!
-ldmfd sp!, {r4-r6,pc}
-
-.pool
+mov r0, #0                  @ For ir:user.
+ldmfd sp!, {r4-r5, pc}
+.pool