efi: Add a command to display the memory map

The EFI memory map is passed from the stub to U-Boot in a table. Add a
command to display it in a vaguely readable fashion.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested on QEMU
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/common/Makefile b/common/Makefile
index d6c1d48..6dc4c89 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -90,6 +90,7 @@
 obj-$(CONFIG_CMD_ECHO) += cmd_echo.o
 obj-$(CONFIG_ENV_IS_IN_EEPROM) += cmd_eeprom.o
 obj-$(CONFIG_CMD_EEPROM) += cmd_eeprom.o
+obj-$(CONFIG_EFI_STUB) += cmd_efi.o
 obj-$(CONFIG_CMD_ELF) += cmd_elf.o
 obj-$(CONFIG_SYS_HUSH_PARSER) += cmd_exit.o
 obj-$(CONFIG_CMD_EXT4) += cmd_ext4.o
diff --git a/common/cmd_efi.c b/common/cmd_efi.c
new file mode 100644
index 0000000..c76296e
--- /dev/null
+++ b/common/cmd_efi.c
@@ -0,0 +1,257 @@
+/*
+ * (C) Copyright 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <efi.h>
+#include <errno.h>
+#include <malloc.h>
+
+static const char *const type_name[] = {
+	"reserved",
+	"loader_code",
+	"loader_data",
+	"bs_code",
+	"bs_data",
+	"rt_code",
+	"rt_data",
+	"conv",
+	"unusable",
+	"acpi_reclaim",
+	"acpi_nvs",
+	"io",
+	"io_port",
+	"pal_code",
+};
+
+static struct attr_info {
+	int shift;
+	const char *name;
+} mem_attr[] = {
+	{ EFI_MEMORY_UC_SHIFT, "uncached" },
+	{ EFI_MEMORY_WC_SHIFT, "write-coalescing" },
+	{ EFI_MEMORY_WT_SHIFT, "write-through" },
+	{ EFI_MEMORY_WB_SHIFT, "write-back" },
+	{ EFI_MEMORY_UCE_SHIFT, "uncached & exported" },
+	{ EFI_MEMORY_WP_SHIFT, "write-protect" },
+	{ EFI_MEMORY_RP_SHIFT, "read-protect" },
+	{ EFI_MEMORY_XP_SHIFT, "execute-protect" },
+	{ EFI_MEMORY_RUNTIME_SHIFT, "needs runtime mapping" }
+};
+
+/* Maximum different attribute values we can track */
+#define ATTR_SEEN_MAX	30
+
+static inline bool is_boot_services(int type)
+{
+	return type == EFI_LOADER_CODE || type == EFI_LOADER_DATA ||
+		type == EFI_BOOT_SERVICES_CODE ||
+		type == EFI_BOOT_SERVICES_DATA;
+}
+
+static int h_cmp_entry(const void *v1, const void *v2)
+{
+	const struct efi_mem_desc *desc1 = v1;
+	const struct efi_mem_desc *desc2 = v2;
+	int64_t diff = desc1->physical_start - desc2->physical_start;
+
+	/*
+	 * Manually calculate the difference to avoid sign loss in the 64-bit
+	 * to 32-bit conversion
+	 */
+	return diff < 0 ? -1 : diff > 0 ? 1 : 0;
+}
+
+void *efi_build_mem_table(struct efi_entry_memmap *map, int size, bool skip_bs)
+{
+	struct efi_mem_desc *desc, *end, *base, *dest, *prev;
+	int count;
+	u64 addr;
+
+	base = malloc(size + sizeof(*desc));
+	if (!base) {
+		debug("%s: Cannot allocate %#x bytes\n", __func__, size);
+		return NULL;
+	}
+	end = (struct efi_mem_desc *)((ulong)map + size);
+	count = ((ulong)end - (ulong)map->desc) / map->desc_size;
+	memcpy(base, map->desc, (ulong)end - (ulong)map->desc);
+	qsort(base, count, map->desc_size, h_cmp_entry);
+	prev = NULL;
+	addr = 0;
+	dest = base;
+	end = base + count;
+	for (desc = base; desc < end; desc = efi_get_next_mem_desc(map, desc)) {
+		bool merge = true;
+		int type = desc->type;
+
+		if (skip_bs && is_boot_services(desc->type))
+			type = EFI_CONVENTIONAL_MEMORY;
+
+		memcpy(dest, desc, map->desc_size);
+		dest->type = type;
+		if (!skip_bs || !prev)
+			merge = false;
+		else if (desc->physical_start != addr)
+			merge = false;
+		else if (type != EFI_CONVENTIONAL_MEMORY)
+			merge = false;
+		else if (prev->type != EFI_CONVENTIONAL_MEMORY)
+			merge = false;
+
+		if (merge) {
+			prev->num_pages += desc->num_pages;
+		} else {
+			prev = dest;
+			dest = efi_get_next_mem_desc(map, dest);
+		}
+		addr = desc->physical_start + (desc->num_pages <<
+				EFI_PAGE_SHIFT);
+	}
+
+	/* Mark the end */
+	dest->type = EFI_TABLE_END;
+
+	return base;
+}
+
+static void efi_print_mem_table(struct efi_entry_memmap *map,
+				struct efi_mem_desc *desc, bool skip_bs)
+{
+	u64 attr_seen[ATTR_SEEN_MAX];
+	int attr_seen_count;
+	int upto, i;
+	u64 addr;
+
+	printf(" #  %-14s  %10s  %10s  %10s  %s\n", "Type", "Physical",
+	       "Virtual", "Size", "Attributes");
+
+	/* Keep track of all the different attributes we have seen */
+	attr_seen_count = 0;
+	addr = 0;
+	for (upto = 0; desc->type != EFI_TABLE_END;
+	     upto++, desc = efi_get_next_mem_desc(map, desc)) {
+		const char *name;
+		u64 size;
+
+		if (skip_bs && is_boot_services(desc->type))
+			continue;
+		if (desc->physical_start != addr) {
+			printf("    %-14s  %010llx  %10s  %010llx\n", "<gap>",
+			       addr, "", desc->physical_start - addr);
+		}
+		size = desc->num_pages << EFI_PAGE_SHIFT;
+
+		name = desc->type < ARRAY_SIZE(type_name) ?
+				type_name[desc->type] : "<invalid>";
+		printf("%2d  %x:%-12s  %010llx  %010llx  %010llx  ", upto,
+		       desc->type, name, desc->physical_start,
+		       desc->virtual_start, size);
+		if (desc->attribute & EFI_MEMORY_RUNTIME)
+			putc('r');
+		printf("%llx", desc->attribute & ~EFI_MEMORY_RUNTIME);
+		putc('\n');
+
+		for (i = 0; i < attr_seen_count; i++) {
+			if (attr_seen[i] == desc->attribute)
+				break;
+		}
+		if (i == attr_seen_count && i < ATTR_SEEN_MAX)
+			attr_seen[attr_seen_count++] = desc->attribute;
+		addr = desc->physical_start + size;
+	}
+
+	printf("\nAttributes key:\n");
+	for (i = 0; i < attr_seen_count; i++) {
+		u64 attr = attr_seen[i];
+		bool first;
+		int j;
+
+		printf("%c%llx: ", attr & EFI_MEMORY_RUNTIME ? 'r' : ' ',
+		       attr & ~EFI_MEMORY_RUNTIME);
+		for (j = 0, first = true; j < ARRAY_SIZE(mem_attr); j++) {
+			if (attr & (1ULL << mem_attr[j].shift)) {
+				if (first)
+					first = false;
+				else
+					printf(", ");
+				printf("%s", mem_attr[j].name);
+			}
+		}
+		putc('\n');
+	}
+	if (skip_bs)
+		printf("*Some areas are merged (use 'all' to see)\n");
+}
+
+static int do_efi_mem(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct efi_mem_desc *desc;
+	struct efi_entry_memmap *map;
+	int size, ret;
+	bool skip_bs;
+
+	skip_bs = !argc || *argv[0] != 'a';
+	ret = efi_info_get(EFIET_MEMORY_MAP, (void **)&map, &size);
+	switch (ret) {
+	case -ENOENT:
+		printf("No EFI table available\n");
+		goto done;
+	case -EPROTONOSUPPORT:
+		printf("Incorrect EFI table version\n");
+		goto done;
+	}
+	printf("EFI table at %lx, memory map %p, size %x, version %x, descr. size %#x\n",
+	       gd->arch.table, map, size, map->version, map->desc_size);
+	if (map->version != EFI_MEM_DESC_VERSION) {
+		printf("Incorrect memory map version\n");
+		ret = -EPROTONOSUPPORT;
+		goto done;
+	}
+
+	desc = efi_build_mem_table(map, size, skip_bs);
+	if (!desc) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	efi_print_mem_table(map, desc, skip_bs);
+	free(desc);
+done:
+	if (ret)
+		printf("Error: %d\n", ret);
+
+	return ret ? CMD_RET_FAILURE : 0;
+}
+
+static cmd_tbl_t efi_commands[] = {
+	U_BOOT_CMD_MKENT(mem, 1, 1, do_efi_mem, "", ""),
+};
+
+static int do_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	cmd_tbl_t *efi_cmd;
+	int ret;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+	efi_cmd = find_cmd_tbl(argv[1], efi_commands, ARRAY_SIZE(efi_commands));
+	argc -= 2;
+	argv += 2;
+	if (!efi_cmd || argc > efi_cmd->maxargs)
+		return CMD_RET_USAGE;
+
+	ret = efi_cmd->cmd(efi_cmd, flag, argc, argv);
+
+	return cmd_process_error(efi_cmd, ret);
+}
+
+U_BOOT_CMD(
+	efi,     3,      1,      do_efi,
+	"EFI access",
+	"mem [all]        Dump memory information [include boot services]"
+);