From ea8f9f466793753da2f53b8501517a466dad1cd6 Mon Sep 17 00:00:00 2001
From: TuxSH <1922548+TuxSH@users.noreply.github.com>
Date: Fri, 6 May 2022 19:53:27 +0100
Subject: [PATCH] loader: refactor part around HIO

---
 sysmodules/loader/source/loader.c | 88 ++++++++++---------------------
 sysmodules/pm/source/info.c       |  2 +
 2 files changed, 30 insertions(+), 60 deletions(-)

diff --git a/sysmodules/loader/source/loader.c b/sysmodules/loader/source/loader.c
index d0d8a28..cb98d57 100644
--- a/sysmodules/loader/source/loader.c
+++ b/sysmodules/loader/source/loader.c
@@ -154,26 +154,21 @@ static Result loadCode(u64 titleId, prog_addrs_t *shared, u64 programHandle, int
     return 0;
 }
 
+static inline bool IsHioId(u64 id)
+{
+    // FS load HIO titles at boot when it can. For HIO titles, title/programId and "program handle"
+    // are the same thing, although some of them can be aliased with their "real" titleId (i.e. in ExHeader).
+
+    if (id >> 32 == 0xFFFF0000u)
+        return true;
+    else
+        return R_LEVEL(FSREG_CheckHostLoadId(id)) == RL_SUCCESS; // check if this is an alias to an HIO-loaded title
+}
+
 static Result GetProgramInfo(ExHeader_Info *exheaderInfo, u64 programHandle)
 {
-    Result res = 0;
-
-    if (programHandle >> 32 == 0xFFFF0000)
-        res = FSREG_GetProgramInfo(exheaderInfo, 1, programHandle);
-    else
-    {
-        res = FSREG_CheckHostLoadId(programHandle);
-        //if ((res >= 0 && (unsigned)res >> 27) || (res < 0 && ((unsigned)res >> 27)-32))
-        //so use PXIPM if FSREG fails OR returns "info", is the second condition a bug?
-        if (R_FAILED(res) || (R_SUCCEEDED(res) && R_LEVEL(res) != RL_SUCCESS))
-        {
-            TRY(PXIPM_GetProgramInfo(exheaderInfo, programHandle));
-        }
-        else
-        {
-            TRY(FSREG_GetProgramInfo(exheaderInfo, 1, programHandle));
-        }
-    }
+    Result res;
+    TRY(IsHioId(programHandle) ? FSREG_GetProgramInfo(exheaderInfo, 1, programHandle) : PXIPM_GetProgramInfo(exheaderInfo, programHandle));
 
     // Tweak 3dsx placeholder title exheaderInfo
     if (hbldrIs3dsxTitle(exheaderInfo->aci.local_caps.title_id))
@@ -287,56 +282,29 @@ static Result RegisterProgram(u64 *programHandle, FS_ProgramInfo *title, FS_Prog
     u64 titleId;
 
     titleId = title->programId;
-    if (titleId >> 32 != 0xFFFF0000)
+    if (IsHioId(titleId))
     {
-        res = FSREG_CheckHostLoadId(titleId);
-        //if ((res >= 0 && (unsigned)res >> 27) || (res < 0 && ((unsigned)res >> 27)-32))
-        if (R_FAILED(res) || (R_SUCCEEDED(res) && R_LEVEL(res) != RL_SUCCESS))
-        {
-            TRY(PXIPM_RegisterProgram(programHandle, title, update));
-            if (*programHandle >> 32 != 0xFFFF0000)
-            {
-                res = FSREG_CheckHostLoadId(*programHandle);
-                //if ((res >= 0 && (unsigned)res >> 27) || (res < 0 && ((unsigned)res >> 27)-32))
-                if (R_FAILED(res) || (R_SUCCEEDED(res) && R_LEVEL(res) != RL_SUCCESS))
-                {
-                    return 0;
-                }
-            }
-            panic(0);
-        }
+        if ((title->mediaType != update->mediaType) || (titleId != update->programId))
+            panic(1);
+
+        TRY(FSREG_LoadProgram(programHandle, title));
+
+        if (!IsHioId(*programHandle)) // double check this is indeed HIO
+            panic(2);
+    }
+    else
+    {
+        TRY(PXIPM_RegisterProgram(programHandle, title, update));
+        if (IsHioId(*programHandle)) // double check this is indeed *not* HIO
+            panic(0);
     }
-
-    if ((title->mediaType != update->mediaType) || (titleId != update->programId))
-        panic(1);
-
-    TRY(FSREG_LoadProgram(programHandle, title));
-    if (*programHandle >> 32 == 0xFFFF0000)
-        return 0;
-
-    res = FSREG_CheckHostLoadId(*programHandle);
-    //if ((res >= 0 && (unsigned)res >> 27) || (res < 0 && ((unsigned)res >> 27)-32))
-    if (R_FAILED(res) || (R_SUCCEEDED(res) && R_LEVEL(res) != RL_SUCCESS))
-        panic(2);
 
     return res;
 }
 
 static Result UnregisterProgram(u64 programHandle)
 {
-    Result res;
-
-    if (programHandle >> 32 == 0xFFFF0000)
-        return FSREG_UnloadProgram(programHandle);
-    else
-    {
-        res = FSREG_CheckHostLoadId(programHandle);
-        //if ((res >= 0 && (unsigned)res >> 27) || (res < 0 && ((unsigned)res >> 27)-32))
-        if (R_FAILED(res) || (R_SUCCEEDED(res) && R_LEVEL(res) != RL_SUCCESS))
-            return PXIPM_UnregisterProgram(programHandle);
-        else
-            return FSREG_UnloadProgram(programHandle);
-    }
+    return IsHioId(programHandle) ? FSREG_UnloadProgram(programHandle) : PXIPM_UnregisterProgram(programHandle);
 }
 
 void loaderHandleCommands(void *ctx)
diff --git a/sysmodules/pm/source/info.c b/sysmodules/pm/source/info.c
index d8b5a16..7452cd6 100644
--- a/sysmodules/pm/source/info.c
+++ b/sysmodules/pm/source/info.c
@@ -12,6 +12,8 @@ Result registerProgram(u64 *programHandle, const FS_ProgramInfo *programInfo, co
 
     if (IS_N3DS) {
         if (pi.programId >> 48 == 0xFFFF) {
+            // Check for HIO TIDs. PM is a bit more lax, as the condition
+            // in Loader and FS is (x >> 32) == 0xFFFF0000 instead.
             return LOADER_RegisterProgram(programHandle, &pi, &piu);
         }
         pi.programId = (pi.programId  & ~N3DS_TID_MASK) | N3DS_TID_BIT;