WOOHOO I BROKE UMD READING WITHOUT CRASHING

.ccls

@@ -1,2 +1,11 @@
 gcc
+-I/home/karim/GitRepos/ARK-4/common/include
+-I/home/karim/GitRepos/ARK-4/core/systemctrl/include
+-I/usr/local/pspdev/psp/include
 -I/usr/local/pspdev/psp/sdk/include
+-I.
+-std=c99
+-Os
+-G0
+-D_PSP_FW_VERSION=660
+-D__CCLS__

.gitignore

@@ -3,3 +3,4 @@ PARAM.SFO
 *.o
 *.elf
 *.prx
+*.a

main.c

@@ -11,30 +11,101 @@
  */
 
 #include <pspkernel.h>
+#include <systemctrl.h>
 #include <string.h>
 
-PSP_MODULE_INFO("umd_livepatch", PSP_MODULE_KERNEL, 0, 8);
+PSP_MODULE_INFO("umd_livepatch", PSP_MODULE_KERNEL, 2, 1);
 
 int module_found = 0;
 int loader_found = 0;
 
+PspIoDrvFuncs reserveUmdFuncs;
+
+PspIoDrvFuncs patchedUmdFuncs;
+
+PspIoDrv originalUmdDriver;
+
+PspIoDrv reserveUmdDriver = {
+    .name = "umdraw",
+    .dev_type = 4,
+    .unk2 = 0x800,
+    .name2 = "UMD_RAW",
+    .funcs = &reserveUmdFuncs
+};
+
+PspIoDrv patchedUmdDriver = {
+    .name = "umd",
+    .dev_type = 4, // block device
+    .unk2 = 0x800,
+    .name2 = "UMD9660",
+    .funcs = &patchedUmdFuncs
+};
+
 #define MAX_MODULE_NUMBER 256
 
 
+// Bogus read to test intercepting
+static int patched_IoRead(PspIoDrvFileArg *arg, char *data, int len)
+{
+    Kprintf("Reading UMD data, hum dee dum...\n");
+    return reserveUmdFuncs.IoRead(arg, data, len);
+}
+
 int module_start(SceSize argc, void *argp)
 {
+    PspIoDrv *umdDriver = 0;
+    int ret;
+
     Kprintf("------------------\nUMD Livepatch starting...\n");
 #ifdef CUSTOM_PATH
     //get_plugin_path(argp);
 #endif
+
+    umdDriver = sctrlHENFindDriver("umd");
+    if (umdDriver) {
+        originalUmdDriver = *umdDriver;
+        reserveUmdFuncs = *umdDriver->funcs;
+        Kprintf("Found UMD driver at 0x%08x\n", umdDriver);
+    } else {
+        Kprintf("Could not find UMD driver...\n");
+        return 1;
+    }
+
+    patchedUmdFuncs = reserveUmdFuncs;
+
+    patchedUmdFuncs.IoRead = &patched_IoRead;
+
+    if (ret = sceIoAddDrv(&reserveUmdDriver)) {
+        Kprintf("Reserve failed: 0x%08x\n", ret);
+        return ret;
+    } else {
+        Kprintf("Reserved previous UMD driver!\n");
+    }
+
+    sceIoDelDrv("umd");
+
+    if (ret = sceIoAddDrv(&patchedUmdDriver)) {
+        Kprintf("Install failed: 0x%08x\n", ret);
+        return ret;
+    } else {
+        Kprintf("Installed our own UMD driver!\n");
+    }
+    return 0;
 }
 
 int module_stop(void)
 {
     Kprintf("Unloading UMD Livepatch.");
+    sceIoDelDrv("umd");
+
+    sceIoAddDrv(&originalUmdDriver);
+    sceIoDelDrv("umdraw");
+    Kprintf("Restored original UMD driver.\n");
+    return 0;
 }
 
 
+
 void infernoSetDiscType(void) {}
 void infernoCacheSetPolicy(void) {}
 void infernoCacheInit(void) {}