Add custom pm sysmodule

sysmodules/pm/source/firmlaunch.c

@@ -0,0 +1,56 @@
+#include <3ds.h>
+#include <string.h>
+#include "firmlaunch.h"
+#include "termination.h"
+#include "task_runner.h"
+#include "util.h"
+
+static void *const g_firmlaunchParameters = (void *)0x12000000;
+
+void mapFirmlaunchParameters(void)
+{
+    assertSuccess(svcKernelSetState(3, 0, g_firmlaunchParameters));
+}
+
+Result GetFirmlaunchParams(void *outParams, size_t size)
+{
+    size = size >= 0x1000 ? 0x1000 : size;
+    memcpy(outParams, g_firmlaunchParameters, size);
+    return 0;
+}
+
+Result SetFirmlaunchParams(const void *params, size_t size)
+{
+    size = size >= 0x1000 ? 0x1000 : size;
+    memcpy(g_firmlaunchParameters, params, size);
+    if (size < 0x1000) {
+        memset(g_firmlaunchParameters + size, 0, 0x1000 - size);
+    }
+    return 0;
+}
+
+static void LaunchFirmAsync(void *argdata)
+{
+    struct {
+        u32 firmTidLow;
+    } *args = argdata;
+
+    terminateAllProcesses((u32)-1, 4 * 1000 * 1000 * 1000LL);
+    // pm has dead code there (notification 0x179, but there's no 'caller process'... (-1))
+
+    u64 firmTid = args->firmTidLow; // note: tidHigh doesn't matter
+    firmTid = IS_N3DS ? (firmTid & ~N3DS_TID_MASK) | N3DS_TID_BIT : firmTid;
+    assertSuccess(svcKernelSetState(0, firmTid));
+}
+
+Result LaunchFirm(u32 firmTidLow, const void *params, size_t size)
+{
+    struct {
+        u32 firmTidLow;
+    } args = { firmTidLow };
+
+    SetFirmlaunchParams(params, size);
+    TaskRunner_RunTask(LaunchFirmAsync, &args, sizeof(args));
+
+    return 0;
+}