Bootmgr: add new module

src/detection/bootmgr/bootmgr_linux.c

@@ -0,0 +1,45 @@
+#include "bootmgr.h"
+#include "common/io/io.h"
+#include "efi.h"
+
+#define FF_EFIVARS_PATH_PREFIX "/sys/firmware/efi/efivars/"
+
+const char* ffDetectBootmgr(FFBootmgrResult* result)
+{
+    uint8_t buffer[2048];
+
+    if (ffReadFileData(FF_EFIVARS_PATH_PREFIX "BootCurrent-" FF_EFI_GLOBAL_GUID, sizeof(buffer), buffer) != 6)
+        return "Failed to read efivar: BootCurrent";
+
+    uint16_t value = *(uint16_t *)&buffer[4];
+    snprintf((char*) buffer, sizeof(buffer), FF_EFIVARS_PATH_PREFIX "Boot%04X-" FF_EFI_GLOBAL_GUID, value);
+
+    ssize_t size = ffReadFileData((const char*) buffer, sizeof(buffer), buffer);
+    if (size < 5 + (int) sizeof(FFEfiLoadOption) || size == (ssize_t) sizeof(buffer))
+        return "Failed to read efivar: Boot####";
+
+    FFEfiLoadOption *efiOption = (FFEfiLoadOption *)&buffer[4];
+    uint32_t descLen = 0;
+    while (efiOption->Description[descLen]) ++descLen;
+
+    if (descLen)
+        ffEfiUcs2ToUtf8(efiOption->Description, &result->name);
+
+    for (
+        ffEfiDevicePathProtocol* filePathList = (void*) &efiOption->Description[descLen + 1];
+        filePathList->Type != 0x7F; // End of Hardware Device Path
+        filePathList = (void*) ((uint8_t*) filePathList + filePathList->Length))
+    {
+        if (filePathList->Type == 4 && filePathList->SubType == 4)
+        {
+            // https://uefi.org/specs/UEFI/2.10/10_Protocols_Device_Path_Protocol.html#file-path-media-device-path
+            ffEfiUcs2ToUtf8((uint16_t*) filePathList->SpecificDevicePathData, &result->firmware);
+            break;
+        }
+    }
+
+    if (ffReadFileData(FF_EFIVARS_PATH_PREFIX "SecureBoot-" FF_EFI_GLOBAL_GUID, sizeof(buffer), buffer) == 6)
+        result->secureBoot = buffer[4] == 1;
+
+    return NULL;
+}