cmd: provide command to display SMBIOS information

U-Boot can either generated an SMBIOS table or copy it from a prior boot
stage, e.g. QEMU.

Provide a command to display the SMBIOS information.

Currently only type 1 and 2 are translated to human readable text.
Other types may be added later. Currently only a hexdump and the list of
strings is provided for these.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 06aae30..a86b570 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -232,6 +232,12 @@
 	help
 	  Display information about the SBI implementation.
 
+config CMD_SMBIOS
+	bool "smbios"
+	depends on SMBIOS
+	help
+	  Display the SMBIOS information.
+
 endmenu
 
 menu "Boot commands"
diff --git a/cmd/Makefile b/cmd/Makefile
index e2a2b16..87133cc 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -168,6 +168,7 @@
 obj-$(CONFIG_CMD_SETEXPR_FMT) += printf.o
 obj-$(CONFIG_CMD_SPI) += spi.o
 obj-$(CONFIG_CMD_STRINGS) += strings.o
+obj-$(CONFIG_CMD_SMBIOS) += smbios.o
 obj-$(CONFIG_CMD_SMC) += smccc.o
 obj-$(CONFIG_CMD_SYSBOOT) += sysboot.o
 obj-$(CONFIG_CMD_STACKPROTECTOR_TEST) += stackprot_test.o
diff --git a/cmd/smbios.c b/cmd/smbios.c
new file mode 100644
index 0000000..feebf93
--- /dev/null
+++ b/cmd/smbios.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * The 'smbios' command displays information from the SMBIOS table.
+ *
+ * Copyright (c) 2023, Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
+ */
+
+#include <command.h>
+#include <hexdump.h>
+#include <mapmem.h>
+#include <smbios.h>
+#include <tables_csum.h>
+#include <asm/global_data.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * smbios_get_string() - get SMBIOS string from table
+ *
+ * @table:	SMBIOS table
+ * @index:	index of the string
+ * Return:	address of string, may point to empty string
+ */
+static const char *smbios_get_string(void *table, int index)
+{
+	const char *str = (char *)table +
+			  ((struct smbios_header *)table)->length;
+
+	if (!*str)
+		++str;
+	for (--index; *str && index; --index)
+		str += strlen(str) + 1;
+
+	return str;
+}
+
+static struct smbios_header *next_table(struct smbios_header *table)
+{
+	const char *str;
+
+	if (table->type == SMBIOS_END_OF_TABLE)
+		return NULL;
+
+	str = smbios_get_string(table, 0);
+	return (struct smbios_header *)(++str);
+}
+
+static void smbios_print_generic(struct smbios_header *table)
+{
+	char *str = (char *)table + table->length;
+
+	if (CONFIG_IS_ENABLED(HEXDUMP)) {
+		printf("Header and Data:\n");
+		print_hex_dump("\t", DUMP_PREFIX_OFFSET, 16, 1,
+			       table, table->length, false);
+	}
+	if (*str) {
+		printf("Strings:\n");
+		for (int index = 1; *str; ++index) {
+			printf("\tString %u: %s\n", index, str);
+			str += strlen(str) + 1;
+		}
+	}
+}
+
+void smbios_print_str(const char *label, void *table, u8 index)
+{
+	printf("\t%s: %s\n", label, smbios_get_string(table, index));
+}
+
+static void smbios_print_type1(struct smbios_type1 *table)
+{
+	printf("System Information\n");
+	smbios_print_str("Manufacturer", table, table->manufacturer);
+	smbios_print_str("Product Name", table, table->product_name);
+	smbios_print_str("Version", table, table->version);
+	smbios_print_str("Serial Number", table, table->serial_number);
+	if (table->length >= 0x19) {
+		printf("\tUUID %pUl\n", table->uuid);
+		smbios_print_str("Wake Up Type", table, table->serial_number);
+	}
+	if (table->length >= 0x1b) {
+		smbios_print_str("Serial Number", table, table->serial_number);
+		smbios_print_str("SKU Number", table, table->sku_number);
+	}
+}
+
+static void smbios_print_type2(struct smbios_type2 *table)
+{
+	u16 *handle;
+
+	printf("Base Board Information\n");
+	smbios_print_str("Manufacturer", table, table->manufacturer);
+	smbios_print_str("Product Name", table, table->product_name);
+	smbios_print_str("Version", table, table->version);
+	smbios_print_str("Serial Number", table, table->serial_number);
+	smbios_print_str("Asset Tag", table, table->asset_tag_number);
+	printf("\tFeature Flags: 0x%2x\n", table->feature_flags);
+	smbios_print_str("Chassis Location", table, table->chassis_location);
+	printf("\tChassis Handle: 0x%2x\n", table->chassis_handle);
+	smbios_print_str("Board Type", table, table->board_type);
+	printf("\tContained Object Handles: ");
+	handle = (void *)table->eos;
+	for (int i = 0; i < table->number_contained_objects; ++i)
+		printf("0x%04x ", handle[i]);
+	printf("\n");
+}
+
+static void smbios_print_type127(struct smbios_type127 *table)
+{
+	printf("End Of Table\n");
+}
+
+static int do_smbios(struct cmd_tbl *cmdtp, int flag, int argc,
+		     char *const argv[])
+{
+	ulong addr;
+	void *entry;
+	u32 size;
+	char version[12];
+	struct smbios_header *table;
+	static const char smbios_sig[] = "_SM_";
+	static const char smbios3_sig[] = "_SM3_";
+	size_t count = 0;
+	u32 max_struct_size;
+
+	addr = gd_smbios_start();
+	if (!addr) {
+		log_warning("SMBIOS not available\n");
+		return CMD_RET_FAILURE;
+	}
+	entry = map_sysmem(addr, 0);
+	if (!memcmp(entry, smbios3_sig, sizeof(smbios3_sig) - 1)) {
+		struct smbios3_entry *entry3 = entry;
+
+		table = (void *)(uintptr_t)entry3->struct_table_address;
+		snprintf(version, sizeof(version), "%d.%d.%d",
+			 entry3->major_ver, entry3->minor_ver, entry3->doc_rev);
+		table = (void *)(uintptr_t)entry3->struct_table_address;
+		size = entry3->length;
+		max_struct_size = entry3->max_struct_size;
+	} else if (!memcmp(entry, smbios_sig, sizeof(smbios_sig) - 1)) {
+		struct smbios_entry *entry2 = entry;
+
+		snprintf(version, sizeof(version), "%d.%d",
+			 entry2->major_ver, entry2->minor_ver);
+		table = (void *)(uintptr_t)entry2->struct_table_address;
+		size = entry2->length;
+		max_struct_size = entry2->max_struct_size;
+	} else {
+		log_err("Unknown SMBIOS anchor format\n");
+		return CMD_RET_FAILURE;
+	}
+	if (table_compute_checksum(entry, size)) {
+		log_err("Invalid anchor checksum\n");
+		return CMD_RET_FAILURE;
+	}
+	printf("SMBIOS %s present.\n", version);
+
+	for (struct smbios_header *pos = table; pos; pos = next_table(pos))
+		++count;
+	printf("%zd structures occupying %d bytes\n", count, max_struct_size);
+	printf("Table at 0x%llx\n", (unsigned long long)map_to_sysmem(table));
+
+	for (struct smbios_header *pos = table; pos; pos = next_table(pos)) {
+		printf("\nHandle 0x%04x, DMI type %d, %d bytes at 0x%llx\n",
+		       pos->handle, pos->type, pos->length,
+		       (unsigned long long)map_to_sysmem(pos));
+		switch (pos->type) {
+		case 1:
+			smbios_print_type1((struct smbios_type1 *)pos);
+			break;
+		case 2:
+			smbios_print_type2((struct smbios_type2 *)pos);
+			break;
+		case 127:
+			smbios_print_type127((struct smbios_type127 *)pos);
+			break;
+		default:
+			smbios_print_generic(pos);
+			break;
+		}
+	}
+
+	return CMD_RET_SUCCESS;
+}
+
+U_BOOT_LONGHELP(smbios, "- display SMBIOS information");
+
+U_BOOT_CMD(smbios, 1, 0, do_smbios, "display SMBIOS information",
+	   smbios_help_text);