kernel-stub: Use common print services

Align the kernel stub to the print services that the EBG core uses as
well. That brings coloring, silent boot, and avoids duplicating
logic between both.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

Author: jan-kiszka

Makefile.am

@@ -246,6 +246,7 @@ kernel_stub_name = kernel-stub$(MACHINE_TYPE_NAME).efi
 
 kernel_stub_sources = \
 	loader_interface.c \
+	print.c \
 	kernel-stub/fdt.c \
 	kernel-stub/initrd.c \
 	kernel-stub/main.c

kernel-stub/fdt.c

@@ -1,7 +1,7 @@
 /*
  * EFI Boot Guard, unified kernel stub
  *
- * Copyright (c) Siemens AG, 2022
+ * Copyright (c) Siemens AG, 2022-2026
  *
  * Authors:
  *  Jan Kiszka <jan.kiszka@siemens.com>
@@ -18,6 +18,7 @@
 #include <endian.h>
 
 #include "kernel-stub.h"
+#include "print.h"
 
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 #define BE32_TO_HOST(val)	bswap_32(val)
@@ -163,7 +164,7 @@ static EFI_STATUS clone_fdt(const VOID *fdt, UINTN size,
 	status = BS->AllocatePages(AllocateAnyPages, EfiACPIReclaimMemory,
 				   SIZE_IN_PAGES(size), fdt_buffer);
 	if (EFI_ERROR(status)) {
-		error(L"Error allocating device tree buffer", status);
+		ERROR(L"Failed to allocate device tree buffer\n");
 		return status;
 	}
 	CopyMem((VOID *)(uintptr_t)*fdt_buffer, (VOID*)fdt,
@@ -182,7 +183,7 @@ EFI_STATUS replace_fdt(const VOID *fdt)
 	if (EFI_ERROR(status)) {
 		const FDT_HEADER *header = fdt;
 
-		info(L"Firmware does not provide device tree fixup protocol");
+		WARNING(L"Firmware does not provide device tree fixup protocol\n");
 
 		size = BE32_TO_HOST(header->TotalSize);
 		status = clone_fdt(fdt, size, &fdt_buffer);
@@ -195,7 +196,8 @@ EFI_STATUS replace_fdt(const VOID *fdt)
 		status = protocol->Fixup(protocol, (VOID *) fdt, &size,
 					 EFI_DT_APPLY_FIXUPS);
 		if (status != EFI_BUFFER_TOO_SMALL) {
-			error(L"Device tree fixup: unexpected error", status);
+			ERROR(L"Early device tree fixup failure (%r)\n",
+			      status);
 			return status;
 		}
 
@@ -210,7 +212,7 @@ EFI_STATUS replace_fdt(const VOID *fdt)
 					 EFI_DT_RESERVE_MEMORY);
 		if (EFI_ERROR(status)) {
 			(VOID) BS->FreePages(fdt_buffer, SIZE_IN_PAGES(size));
-			error(L"Device tree fixup failed", status);
+			ERROR(L"Device tree fixup failed (%r)\n", status);
 			return status;
 		}
 	}
@@ -219,7 +221,8 @@ EFI_STATUS replace_fdt(const VOID *fdt)
 					       (VOID *)(uintptr_t)fdt_buffer);
 	if (EFI_ERROR(status)) {
 		(VOID) BS->FreePages(fdt_buffer, SIZE_IN_PAGES(size));
-		error(L"Failed to install alternative device tree", status);
+		ERROR(L"Failed to install alternative device tree (%r)\n",
+		      status);
 	}
 
 	return status;

kernel-stub/initrd.c

@@ -16,6 +16,7 @@
 #include <efilib.h>
 
 #include "kernel-stub.h"
+#include "print.h"
 
 typedef struct {
 	VENDOR_DEVICE_PATH vendor;

kernel-stub/kernel-stub.h

@@ -14,10 +14,6 @@
 
 #include <efi.h>
 
-VOID error(CHAR16 *message, EFI_STATUS status);
-VOID __attribute__((noreturn)) error_exit(CHAR16 *message, EFI_STATUS status);
-VOID info(CHAR16 *message);
-
 const VOID *get_fdt_compatible(VOID);
 BOOLEAN match_fdt(const VOID *fdt, const CHAR8 *compatible);
 EFI_STATUS replace_fdt(const VOID *fdt);

kernel-stub/main.c

@@ -16,8 +16,9 @@
 #include <efilib.h>
 
 #include "kernel-stub.h"
-#include "version.h"
 #include "loader_interface.h"
+#include "print.h"
+#include "version.h"
 
 typedef struct {
 	UINT8 Ignore[60];
@@ -55,7 +56,6 @@ typedef struct {
 	UINT8 Ignore[24];
 } __attribute__((packed)) SECTION;
 
-static EFI_HANDLE this_image;
 static EFI_LOADED_IMAGE kernel_image;
 
 EFI_PHYSICAL_ADDRESS align_addr(EFI_PHYSICAL_ADDRESS ptr,
@@ -64,24 +64,6 @@ EFI_PHYSICAL_ADDRESS align_addr(EFI_PHYSICAL_ADDRESS ptr,
 	return (ptr + align - 1) & ~(align - 1);
 }
 
-VOID info(CHAR16 *message)
-{
-	Print(L"Unified kernel stub: %s\n", message);
-}
-
-VOID error(CHAR16 *message, EFI_STATUS status)
-{
-	Print(L"Unified kernel stub: %s (%r).\n", message, status);
-	(VOID) BS->Stall(3 * 1000 * 1000);
-}
-
-VOID __attribute__((noreturn)) error_exit(CHAR16 *message, EFI_STATUS status)
-{
-	error(message, status);
-	(VOID) BS->Exit(this_image, status, 0, NULL);
-	__builtin_unreachable();
-}
-
 static const PE_HEADER *get_pe_header(const VOID *image)
 {
 	const DOS_HEADER *dos_header = image;
@@ -119,8 +101,10 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 	this_image = image_handle;
 	InitializeLib(image_handle, system_table);
 
-	Print(L"Unified kernel stub (EFI Boot Guard %s)\n",
-	      L"" EFIBOOTGUARD_VERSION);
+#if !defined(SILENT_BOOT)
+	PrintC(EFI_CYAN, L"Unified kernel stub (EFI Boot Guard %s)\n",
+	       L"" EFIBOOTGUARD_VERSION);
+#endif
 
 	fdt_compatible = get_fdt_compatible();
 
@@ -133,7 +117,7 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 
 	/* consider zero-termination for string length */
 	if (stub_image->LoadOptionsSize > sizeof(CHAR16)) {
-		info(L"WARNING: Passed command line options ignored, only built-in used");
+		WARNING(L"Passed command line options ignored, only built-in used\n");
 	}
 
 	pe_header = get_pe_header(stub_image->ImageBase);
@@ -192,14 +176,14 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 	status = BS->AllocatePages(AllocateAnyPages, EfiLoaderData,
 				   kernel_pages, &kernel_buffer);
 	if (EFI_ERROR(status)) {
-		error(L"Error allocating memory for kernel image", status);
+		ERROR(L"Could not allocate memory for kernel image\n");
 		goto cleanup_initrd;
 	}
 
 	aligned_kernel_buffer =
 		align_addr(kernel_buffer, pe_header->Opt.SectionAlignment);
 	if ((uintptr_t) aligned_kernel_buffer != aligned_kernel_buffer) {
-		error(L"Alignment overflow for kernel image", EFI_LOAD_ERROR);
+		ERROR(L"Alignment overflow for kernel image\n");
 		status = EFI_LOAD_ERROR;
 		goto cleanup_buffer;
 	}
@@ -216,7 +200,7 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 			&kernel_handle, &LoadedImageProtocol, &kernel_image,
 			NULL);
 	if (EFI_ERROR(status)) {
-		error(L"Error registering kernel image", status);
+		ERROR(L"Registering kernel image failed (%r)\n", status);
 		goto cleanup_buffer;
 	}
 
@@ -225,20 +209,20 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 		if (EFI_ERROR(status)) {
 			goto cleanup_protocols;
 		}
-		info(L"Using matched embedded device tree");
+		INFO(L"Using matched embedded device tree\n");
 	} else if (fdt_compatible) {
 		if (has_dtbs) {
-			info(L"WARNING: No embedded device tree matched firmware-provided one");
+			WARNING(L"No embedded device tree matched firmware-provided one\n");
 		}
-		info(L"Using firmware-provided device tree");
+		INFO(L"Using firmware-provided device tree\n");
 	}
 
 	UINT16 *boot_medium_uuidstr =
 		disk_get_part_uuid(stub_image->DeviceHandle);
 	bg_interface_params.loader_device_part_uuid = boot_medium_uuidstr;
 	status = set_bg_interface_vars(&bg_interface_params);
 	if (EFI_ERROR(status)) {
-		error(L"could not set interface vars", status);
+		WARNING(L"Could not set interface vars (%r)\n", status);
 	}
 	FreePool(boot_medium_uuidstr);
 
@@ -253,7 +237,7 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 			kernel_handle, &LoadedImageProtocol, &kernel_image,
 			NULL);
 	if (EFI_ERROR(cleanup_status)) {
-		error(L"Error unregistering kernel image", status);
+		ERROR(L"Unregistering kernel image failed (%r)\n", status);
 		if (!EFI_ERROR(status)) {
 			status = cleanup_status;
 		}
@@ -263,5 +247,8 @@ EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 cleanup_initrd:
 	uninstall_initrd_loader();
 
+	if (EFI_ERROR(status)) {
+		(VOID) BS->Stall(3 * 1000 * 1000);
+	}
 	return status;
 }