diff --git a/Tools/StarletBootstrapProbe/StarletBootstrapProbe.cpp b/Tools/StarletBootstrapProbe/StarletBootstrapProbe.cpp
index a6b306d70b..8f76e925b7 100644
--- a/Tools/StarletBootstrapProbe/StarletBootstrapProbe.cpp
+++ b/Tools/StarletBootstrapProbe/StarletBootstrapProbe.cpp
@@ -32,6 +32,22 @@ enum class ExpectedOutcome
 // Exit status of a run stopped by a Dolphin alert (1: failed expectation, 2: usage).
 constexpr int ALERT_EXIT_STATUS = 3;
 
+// StarOS's SBR1 boot record in MEM1 (StarOS crates/boot-contract, report.rs).
+enum class SBR1Mode
+{
+  None,
+  // --sbr1-record: create the record as the loader does, report it after the run.
+  Record,
+  // --sbr1-absent: no record; report the area after the run.
+  Absent,
+};
+constexpr u32 SBR1_BASE = 0x00200000;
+constexpr u32 SBR1_MAGIC = 0x53425231;
+constexpr u32 SBR1_VERSION = 1;
+constexpr u32 SBR1_SIZE = 0x1000;
+constexpr u32 SBR1_EXI_STARLET = 2;
+constexpr u32 SBR1_RELAY_JUMPING = 4;
+
 // Dolphin's default handler shows an alert in a modal MessageBox on Windows, which blocks the
 // probe until someone closes it. Report the alert on stderr and fail the run at once instead.
 bool FailOnAlert(const char* caption, const char* text, bool, Common::MsgType)
@@ -167,14 +183,16 @@ bool Run(const std::string& path, bool jit, bool mmu_faults, ExpectedOutcome exp
 int main(int argc, char** argv)
 {
   Common::RegisterMsgAlertHandler(FailOnAlert);
-  if (argc < 2 || argc > 5)
+  if (argc < 2 || argc > 6)
   {
     std::cerr << "Usage: StarletBootstrapProbe <ELF> [--jit] [--mmu-faults] "
+                 "[--sbr1-record|--sbr1-absent] "
                  "[--expect-panic|--expect-fatal-data|--expect-undefined-fault|--expect-phase2]\n";
     return 2;
   }
   bool jit = false;
   bool mmu_faults = false;
+  SBR1Mode sbr1 = SBR1Mode::None;
   ExpectedOutcome expected = ExpectedOutcome::Idle;
   bool outcome_selected = false;
   for (int index = 2; index < argc; ++index)
@@ -184,6 +202,15 @@ int main(int argc, char** argv)
       jit = true;
     else if (option == "--mmu-faults")
       mmu_faults = true;
+    else if (option == "--sbr1-record" || option == "--sbr1-absent")
+    {
+      if (sbr1 != SBR1Mode::None)
+      {
+        std::cerr << "Select only one SBR1 mode\n";
+        return 2;
+      }
+      sbr1 = option == "--sbr1-record" ? SBR1Mode::Record : SBR1Mode::Absent;
+    }
     else if (option == "--expect-panic" || option == "--expect-fatal-data" ||
              option == "--expect-undefined-fault" || option == "--expect-phase2")
     {
@@ -211,7 +238,34 @@ int main(int argc, char** argv)
   auto& system = Core::System::GetInstance();
   system.SetIsWii(true);
   system.GetMemory().Init();
+  auto& memory = system.GetMemory();
+  if (sbr1 == SBR1Mode::Record)
+  {
+    // As the Broadway loader and the ARM relay leave StarOS's SBR1 boot record before the image
+    // runs (StarOS docs/contracts/wii-dev-boot.md): header, the relay at its last step, EXI
+    // channel 1 given to the Starlet, the magic written last.
+    memory.Write_U32(SBR1_VERSION, SBR1_BASE + 0x04);
+    memory.Write_U32(SBR1_SIZE, SBR1_BASE + 0x08);
+    memory.Write_U32(SBR1_EXI_STARLET, SBR1_BASE + 0x0c);
+    memory.Write_U32(SBR1_RELAY_JUMPING, SBR1_BASE + 0x10);
+    memory.Write_U32(SBR1_MAGIC, SBR1_BASE);
+  }
   const bool passed = Run(argv[1], jit, mmu_faults, expected);
+  if (sbr1 != SBR1Mode::None)
+  {
+    // The record's summary after the run; with --sbr1-absent every word must still be zero.
+    std::cerr << std::hex << "SBR1 magic 0x" << memory.Read_U32(SBR1_BASE) << std::dec
+              << " state " << memory.Read_U32(SBR1_BASE + 0x18) << " reason "
+              << memory.Read_U32(SBR1_BASE + 0x1c) << " owner "
+              << memory.Read_U32(SBR1_BASE + 0x0c) << " fault "
+              << memory.Read_U32(SBR1_BASE + 0x20) << " ring "
+              << memory.Read_U32(SBR1_BASE + 0x2c) << " dropped "
+              << memory.Read_U32(SBR1_BASE + 0x30);
+    u32 written = 0;
+    for (u32 offset = 0; offset < SBR1_SIZE; offset += 4)
+      written += memory.Read_U32(SBR1_BASE + offset) != 0;
+    std::cerr << " nonzero_words " << written << '\n';
+  }
   system.GetMemory().Shutdown();
   return passed ? 0 : 1;
 }