efi: Split out table-listing code into a new file

This code is used with EFI_LOADER but is also useful (with some
modifications) for the EFI app and payload. Move it into a shared
file.

Show the address of the table so it can be examined if needed. Also show
the table name as unknown if necessary. Our list of GUIDs is fairly
small.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/Makefile b/cmd/Makefile
index 7198029..62f50e2 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -63,7 +63,7 @@
 obj-$(CONFIG_ENV_IS_IN_EEPROM) += eeprom.o
 obj-$(CONFIG_CMD_EEPROM) += eeprom.o
 obj-$(CONFIG_EFI) += efi.o
-obj-$(CONFIG_CMD_EFIDEBUG) += efidebug.o
+obj-$(CONFIG_CMD_EFIDEBUG) += efidebug.o efi_common.o
 obj-$(CONFIG_CMD_EFICONFIG) += eficonfig.o
 ifdef CONFIG_CMD_EFICONFIG
 ifdef CONFIG_EFI_MM_COMM_TEE
diff --git a/cmd/efi_common.c b/cmd/efi_common.c
new file mode 100644
index 0000000..f405609
--- /dev/null
+++ b/cmd/efi_common.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Common code for EFI commands
+ *
+ * Copyright 2023 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <efi.h>
+#include <efi_api.h>
+#include <uuid.h>
+
+void efi_show_tables(struct efi_system_table *systab)
+{
+	int i;
+
+	for (i = 0; i < systab->nr_tables; i++) {
+		struct efi_configuration_table *tab = &systab->tables[i];
+		char guid_str[37];
+
+		uuid_bin_to_str(tab->guid.b, guid_str, 1);
+		printf("%p  %pUl  %s\n", tab->table, guid_str,
+		       uuid_guid_get_str(tab->guid.b) ?: "(unknown)");
+	}
+}
diff --git a/cmd/efidebug.c b/cmd/efidebug.c
index e6959ed..9622430 100644
--- a/cmd/efidebug.c
+++ b/cmd/efidebug.c
@@ -649,11 +649,7 @@
 static int do_efi_show_tables(struct cmd_tbl *cmdtp, int flag,
 			      int argc, char *const argv[])
 {
-	efi_uintn_t i;
-
-	for (i = 0; i < systab.nr_tables; ++i)
-		printf("%pUl (%pUs)\n",
-		       &systab.tables[i].guid, &systab.tables[i].guid);
+	efi_show_tables(&systab);
 
 	return CMD_RET_SUCCESS;
 }