diff --git a/android.c b/android.c
index 5dd3923..11741c2 100644
--- a/android.c
+++ b/android.c
@@ -18,7 +18,7 @@ EFI_STATUS android_open_image(struct android_image *image) {
     return EFI_SUCCESS;
 }
 
-EFI_STATUS android_copy_cmdline(struct android_image *image, CHAR8* cmdline, UINTN max_length) {
+EFI_STATUS android_copy_cmdline(const struct android_image *image, CHAR8* cmdline, UINTN max_length) {
     if (max_length <= ANDROID_BOOT_ARGS_SIZE + ANDROID_BOOT_EXTRA_ARGS_SIZE) {
         return EFI_BUFFER_TOO_SMALL;
     }
diff --git a/android.h b/android.h
index 49bcf2b..690d7ab 100644
--- a/android.h
+++ b/android.h
@@ -38,27 +38,27 @@ struct android_image {
 
 EFI_STATUS android_open_image(struct android_image *image);
 
-static inline EFI_STATUS android_read_kernel(struct android_image *image, UINT64 offset, VOID *kernel, UINTN size) {
+static inline EFI_STATUS android_read_kernel(const struct android_image *image, UINT64 offset, VOID *kernel, UINTN size) {
     return image_read(&image->image, image->header.page_size + offset, kernel, size);
 }
 
-static inline EFI_STATUS android_load_kernel(struct android_image *image, UINT64 offset, VOID *kernel) {
+static inline EFI_STATUS android_load_kernel(const struct android_image *image, UINT64 offset, VOID *kernel) {
     return android_read_kernel(image, offset, kernel, image->header.kernel_size - offset);
 }
 
-static inline UINT64 android_ramdisk_offset(struct android_image *image) {
+static inline UINT64 android_ramdisk_offset(const struct android_image *image) {
     UINTN mask = image->header.page_size - 1;
     return image->header.page_size + ((image->header.kernel_size + mask) & ~mask);
 }
 
-static inline UINT32 android_ramdisk_size(struct android_image *image) {
+static inline UINT32 android_ramdisk_size(const struct android_image *image) {
     return image->header.ramdisk_size;
 }
 
-static inline EFI_STATUS android_load_ramdisk(struct android_image *image, VOID *ramdisk) {
+static inline EFI_STATUS android_load_ramdisk(const struct android_image *image, VOID *ramdisk) {
     return image_read(&image->image, android_ramdisk_offset(image), ramdisk, android_ramdisk_size(image));
 }
 
-EFI_STATUS android_copy_cmdline(struct android_image *image, CHAR8* cmdline, UINTN max_length);
+EFI_STATUS android_copy_cmdline(const struct android_image *image, CHAR8* cmdline, UINTN max_length);
 
 #endif //ANDROID_EFI_ANDROID_H
diff --git a/graphics.c b/graphics.c
index fbc8f32..c3967bd 100644
--- a/graphics.c
+++ b/graphics.c
@@ -8,7 +8,7 @@ static inline UINTN center(UINTN i, UINTN max) {
     return i < max ? (max - i) / 2 : 0;
 }
 
-EFI_STATUS graphics_display_image(struct graphics_image *image) {
+EFI_STATUS graphics_display_image(const struct graphics_image *image) {
     EFI_GRAPHICS_OUTPUT_PROTOCOL *graphics_output;
     EFI_STATUS err = LibLocateProtocol(&GraphicsOutputProtocol, (VOID**) &graphics_output);
     if (err) {
diff --git a/graphics.h b/graphics.h
index 431a4e4..692ed8c 100644
--- a/graphics.h
+++ b/graphics.h
@@ -12,6 +12,6 @@ struct graphics_image {
     EFI_GRAPHICS_OUTPUT_BLT_PIXEL *blt;
 };
 
-EFI_STATUS graphics_display_image(struct graphics_image *image);
+EFI_STATUS graphics_display_image(const struct graphics_image *image);
 
 #endif //ANDROID_EFI_GRAPHICS_H
diff --git a/main.c b/main.c
index 7df323e..c2c7c8c 100644
--- a/main.c
+++ b/main.c
@@ -200,8 +200,8 @@ static EFI_STATUS parse_command_line(EFI_LOADED_IMAGE_PROTOCOL *loaded_image, st
     return err;
 }
 
-static EFI_STATUS prepare_cmdline(struct linux_setup_header *kernel_header, struct android_image *android_image,
-        struct android_efi_options *options) {
+static EFI_STATUS prepare_cmdline(struct linux_setup_header *kernel_header, const struct android_image *android_image,
+        const struct android_efi_options *options) {
     EFI_STATUS err = linux_allocate_cmdline(kernel_header);
     if (err) {
         return err;
@@ -243,7 +243,7 @@ static const CHAR8 *find_initrd_option(const CHAR8 *cmdline) {
 }
 
 static EFI_STATUS load_ramdisk_cmdline(EFI_HANDLE loader_device, const CHAR8 *cmdline,
-        struct linux_setup_header *kernel_header, struct android_image *android_image) {
+        struct linux_setup_header *kernel_header, const struct android_image *android_image) {
     EFI_FILE_HANDLE dir = LibOpenRoot(loader_device);
     if (!dir) {
         Print(L"Failed to open root directory\n");
@@ -335,7 +335,7 @@ static EFI_STATUS load_ramdisk_cmdline(EFI_HANDLE loader_device, const CHAR8 *cm
 }
 
 static EFI_STATUS load_ramdisk(EFI_HANDLE loader_device,
-        struct linux_setup_header *kernel_header, struct android_image *android_image) {
+        struct linux_setup_header *kernel_header, const struct android_image *android_image) {
     const CHAR8 *initrd = find_initrd_option(linux_cmdline_pointer(kernel_header));
     if (initrd) {
         return load_ramdisk_cmdline(loader_device, initrd, kernel_header, android_image);
@@ -350,7 +350,7 @@ static EFI_STATUS load_ramdisk(EFI_HANDLE loader_device,
 }
 
 static EFI_STATUS load_kernel(EFI_HANDLE loader, EFI_HANDLE loader_device,
-                              struct android_efi_options *options, VOID **boot_params) {
+                              const struct android_efi_options *options, VOID **boot_params) {
     struct android_image android_image;
     EFI_STATUS err = image_open(&android_image.image, loader, loader_device, options->partition_guid, options->path);
     if (options->path) {
@@ -412,7 +412,7 @@ static EFI_STATUS load_kernel(EFI_HANDLE loader, EFI_HANDLE loader_device,
     return err;
 }
 
-extern struct graphics_image splash_image;
+extern const struct graphics_image splash_image;
 
 EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *system_table) {
     InitializeLib(image, system_table);
diff --git a/png2efi/png2efi.c b/png2efi/png2efi.c
index 20588fa..c2a0758 100644
--- a/png2efi/png2efi.c
+++ b/png2efi/png2efi.c
@@ -20,7 +20,7 @@ static int write_image(const char *identifier, const char *filename, png_image *
     }
 
     fprintf(file, "};\n");
-    fprintf(file, "struct graphics_image %s_image = {%u, %u, %s_blt};\n",
+    fprintf(file, "const struct graphics_image %s_image = {%u, %u, %s_blt};\n",
             identifier, image->width, image->height, identifier);
 
     return fclose(file);