core: sboot: Add menu

Signed-off-by: Ian M. <ian@aptel.org>

3 files changed, 72 insertions, 10 deletions

diff --git a/core/menu.c b/core/menu.c
new file mode 100644
index 0000000..955b750
--- /dev/null
+++ b/core/menu.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2026, Apollo Telephone Laboratories.
+ * Provided under the BSD-3 clause.
+ */
+
+#include <sboot/sboot.h>
+#include <sboot/fwi.h>
+#include <sboot/config.h>
+
+#define MENU_CLEAR() \
+    Print(L"\r\t\t\t\t\t\t\r")
+#define MENU_WRITE(ENTRY) \
+    Print(L"<-- %s -->", (ENTRY)->Name);
+
+VOID
+SBootMenu(OUT BOOT_ENTRY *Entry)
+{
+    EFI_INPUT_KEY Key;
+    UINTN CurrentEntryIndex;
+    BOOT_ENTRY *CurrentEntry;
+    EFI_STATUS Status;
+    BOOLEAN Run = TRUE;
+
+    Print(L" ===== USE LEFT/RIGHT ARROW KEYS TO SELECT ====\n\n");
+    CurrentEntryIndex = 0;
+    CurrentEntry = &ConfigBootEntries[CurrentEntryIndex];
+    MENU_WRITE(CurrentEntry);
+
+    while (Run) {
+        Status = uefi_call_wrapper(gST->ConIn->ReadKeyStroke, 2, gST->ConIn, &Key);
+        if (EFI_ERROR(Status)) {
+            continue;
+        }
+
+        switch (Key.ScanCode) {
+        case 0x0:
+            Run = FALSE;
+            continue;
+        case SCAN_RIGHT:
+            if (CurrentEntryIndex < NELEM(ConfigBootEntries) - 2) {
+                ++CurrentEntryIndex;
+                CurrentEntry = &ConfigBootEntries[CurrentEntryIndex];
+                MENU_CLEAR();
+                MENU_WRITE(CurrentEntry);
+            }
+            break;
+        case SCAN_LEFT:
+            if (CurrentEntryIndex == 0)
+                continue;
+
+            --CurrentEntryIndex;
+            CurrentEntry = &ConfigBootEntries[CurrentEntryIndex];
+            MENU_CLEAR();
+            MENU_WRITE(CurrentEntry);
+            break;
+        }
+    }
+
+    Print(L"\nBooting %s (%s)\n", CurrentEntry->Name, CurrentEntry->BootPath);
+    *Entry = *CurrentEntry;
+}
diff --git a/core/sboot.c b/core/sboot.c
index 1649b7e..1a3d7d1 100644
--- a/core/sboot.c
+++ b/core/sboot.c
@@ -13,18 +13,9 @@ EFI_STATUS
 EFIAPI
 efi_main(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
 {
-    UINTN NrBootEntries;
-    BOOT_PROTOCOL LastProtocol;
+    BOOT_ENTRY Entry;
 
     InitializeLib(ImageHandle, SystemTable);
-    NrBootEntries = NELEM(ConfigBootEntries);
-
-    /* Ensure the list is terminated */
-    LastProtocol = ConfigBootEntries[NrBootEntries - 1].Protocol;
-    if (LastProtocol != PROTOCOL_END) {
-        Print(L"fatal: boot entry list not terminated\n");
-        Hcf();
-    }
 
     /* Disable the watchdog timer */
     FwiSetWatchdogTimer(
@@ -40,5 +31,6 @@ efi_main(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
         NELEM(ConfigBootEntries) - 1
     );
 
+    SBootMenu(&Entry);
     for (;;);
 }
diff --git a/head/sboot/sboot.h b/head/sboot/sboot.h
index 749fbc7..2efbfa5 100644
--- a/head/sboot/sboot.h
+++ b/head/sboot/sboot.h
@@ -6,6 +6,10 @@
 #ifndef _COMMON_SBOOT_H_
 #define _COMMON_SBOOT_H_ 1
 
+#include <efi.h>
+#include <efilib.h>
+#include <sboot/config.h>
+
 /* Bootloader version */
 #define SBOOT_VERSION L"v0.0.1"
 
@@ -16,4 +20,9 @@
 #define Hcf()   \
     for (;;);
 
+/*
+ * Begin the SBoot selection menu
+ */
+VOID SBootMenu(OUT BOOT_ENTRY *Entry);
+
 #endif  /* !_COMMON_SBOOT_H_ */