Merge patch series "Allow showing the memory map"

Simon Glass <sjg@chromium.org> says:

This little series adds a new 'memmap' command, intended to show the
layout of memory within U-Boot and how much memory is available for
loading images.

Link: https://lore.kernel.org/r/20241021081934.289473-1-sjg@chromium.org

cmd/Kconfig

@@ -885,9 +885,21 @@ config MD5SUM_VERIFY
 
 config CMD_MEMINFO
 	bool "meminfo"
+	default y if SANDBOX
 	help
 	  Display memory information.
 
+config CMD_MEMINFO_MAP
+	bool "- with memory map"
+	depends on CMD_MEMINFO
+	default y if SANDBOX
+	help
+	  Shows a memory map, in addition to just the DRAM size. This allows
+	  seeing where U-Boot's memory area is, at the top of DRAM, as well as
+	  detail about each piece of it.
+
+	  See doc/usage/cmd/meminfo.rst for more information.
+
 config CMD_MEMORY
 	bool "md, mm, nm, mw, cp, cmp, base, loop"
 	default y

cmd/Makefile

@@ -109,6 +109,7 @@ obj-$(CONFIG_CMD_LOG) += log.o
 obj-$(CONFIG_CMD_LSBLK) += lsblk.o
 obj-$(CONFIG_CMD_MD5SUM) += md5sum.o
 obj-$(CONFIG_CMD_MEMORY) += mem.o
+obj-$(CONFIG_CMD_MEMINFO) += meminfo.o
 obj-$(CONFIG_CMD_IO) += io.o
 obj-$(CONFIG_CMD_MII) += mii.o
 obj-$(CONFIG_CMD_MISC) += misc.o

cmd/mem.c

@@ -1379,17 +1379,6 @@ U_BOOT_CMD(
 
 #endif
 
-#ifdef CONFIG_CMD_MEMINFO
-static int do_mem_info(struct cmd_tbl *cmdtp, int flag, int argc,
-		       char *const argv[])
-{
-	puts("DRAM:  ");
-	print_size(gd->ram_size, "\n");
-
-	return 0;
-}
-#endif
-
 U_BOOT_CMD(
 	base,	2,	1,	do_mem_base,
 	"print or set address offset",
@@ -1433,14 +1422,6 @@ U_BOOT_CMD(
 );
 #endif /* CONFIG_CMD_MX_CYCLIC */
 
-#ifdef CONFIG_CMD_MEMINFO
-U_BOOT_CMD(
-	meminfo,	3,	1,	do_mem_info,
-	"display memory information",
-	""
-);
-#endif
-
 #ifdef CONFIG_CMD_RANDOM
 U_BOOT_CMD(
 	random,	4,	0,	do_random,

cmd/meminfo.c

@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <bloblist.h>
+#include <bootstage.h>
+#include <command.h>
+#include <display_options.h>
+#include <lmb.h>
+#include <malloc.h>
+#include <mapmem.h>
+#include <asm/global_data.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static void print_region(const char *name, ulong base, ulong size, ulong *uptop)
+{
+	ulong end = base + size;
+
+	printf("%-12s %8lx %8lx %8lx", name, base, size, end);
+	if (*uptop)
+		printf(" %8lx", *uptop - end);
+	putc('\n');
+	*uptop = base;
+}
+
+static void show_lmb(const struct lmb *lmb, ulong *uptop)
+{
+	int i;
+
+	for (i = lmb->used_mem.count - 1; i >= 0; i--) {
+		const struct lmb_region *rgn = alist_get(&lmb->used_mem, i,
+							 struct lmb_region);
+
+		/*
+		 * Assume that the top lmb region is the U-Boot region, so just
+		 * take account of the memory not already reported
+		 */
+		if (lmb->used_mem.count - 1)
+			print_region("lmb", rgn->base, *uptop - rgn->base,
+				     uptop);
+		else
+			print_region("lmb", rgn->base, rgn->size, uptop);
+		*uptop = rgn->base;
+	}
+}
+
+static int do_meminfo(struct cmd_tbl *cmdtp, int flag, int argc,
+		      char *const argv[])
+{
+	ulong upto, stk_bot;
+
+	puts("DRAM:  ");
+	print_size(gd->ram_size, "\n");
+
+	if (!IS_ENABLED(CONFIG_CMD_MEMINFO_MAP))
+		return 0;
+
+	printf("\n%-12s %8s %8s %8s %8s\n", "Region", "Base", "Size", "End",
+	       "Gap");
+	printf("------------------------------------------------\n");
+	upto = 0;
+	if (IS_ENABLED(CONFIG_VIDEO))
+		print_region("video", gd_video_bottom(),
+			     gd_video_size(), &upto);
+	if (IS_ENABLED(CONFIG_TRACE))
+		print_region("trace", map_to_sysmem(gd_trace_buff()),
+			     gd_trace_size(), &upto);
+	print_region("code", gd->relocaddr, gd->mon_len, &upto);
+	print_region("malloc", map_to_sysmem((void *)mem_malloc_start),
+		     mem_malloc_end - mem_malloc_start, &upto);
+	print_region("board_info", map_to_sysmem(gd->bd),
+		     sizeof(struct bd_info), &upto);
+	print_region("global_data", map_to_sysmem((void *)gd),
+		     sizeof(struct global_data), &upto);
+	print_region("devicetree", map_to_sysmem(gd->fdt_blob),
+		     fdt_totalsize(gd->fdt_blob), &upto);
+	if (IS_ENABLED(CONFIG_BOOTSTAGE))
+		print_region("bootstage", map_to_sysmem(gd_bootstage()),
+			     bootstage_get_size(false), &upto);
+	if (IS_ENABLED(CONFIG_BLOBLIST))
+		print_region("bloblist", map_to_sysmem(gd_bloblist()),
+			     bloblist_get_total_size(), &upto);
+	stk_bot = gd->start_addr_sp - CONFIG_STACK_SIZE;
+	print_region("stack", stk_bot, CONFIG_STACK_SIZE, &upto);
+	if (IS_ENABLED(CONFIG_LMB))
+		show_lmb(lmb_get(), &upto);
+	print_region("free", gd->ram_base, upto, &upto);
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	meminfo,	1,	1,	do_meminfo,
+	"display memory information",
+	""
+);

common/board_f.c

@@ -501,9 +501,9 @@ static unsigned long reserve_stack_aligned(size_t size)
 static int reserve_noncached(void)
 {
 	/*
-	 * The value of gd->start_addr_sp must match the value of malloc_start
-	 * calculated in board_r.c:initr_malloc(), which is passed to
-	 * dlmalloc.c:mem_malloc_init() and then used by
+	 * The value of gd->start_addr_sp must match the value of
+	 * mem_malloc_start calculated in board_r.c:initr_malloc(), which is
+	 * passed to dlmalloc.c:mem_malloc_init() and then used by
 	 * cache.c:noncached_init()
 	 *
 	 * These calculations must match the code in cache.c:noncached_init()
@@ -582,7 +582,7 @@ static int reserve_fdt(void)
 static int reserve_bootstage(void)
 {
 #ifdef CONFIG_BOOTSTAGE
-	int size = bootstage_get_size();
+	int size = bootstage_get_size(true);
 
 	gd->start_addr_sp = reserve_stack_aligned(size);
 	gd->boardf->new_bootstage = map_sysmem(gd->start_addr_sp, size);

common/board_r.c

@@ -204,8 +204,7 @@ static int initr_malloc(void)
 	 */
 	start = gd->relocaddr - TOTAL_MALLOC_LEN;
 	gd_set_malloc_start(start);
-	mem_malloc_init((ulong)map_sysmem(start, TOTAL_MALLOC_LEN),
-			TOTAL_MALLOC_LEN);
+	mem_malloc_init(start, TOTAL_MALLOC_LEN);
 	return 0;
 }
 

common/bootstage.c

@@ -520,17 +520,19 @@ int _bootstage_unstash_default(void)
 }
 #endif
 
-int bootstage_get_size(void)
+int bootstage_get_size(bool add_strings)
 {
-	struct bootstage_data *data = gd->bootstage;
-	struct bootstage_record *rec;
 	int size;
-	int i;
 
 	size = sizeof(struct bootstage_data);
-	for (rec = data->record, i = 0; i < data->rec_count;
-	     i++, rec++)
-		size += strlen(rec->name) + 1;
+	if (add_strings) {
+		struct bootstage_data *data = gd->bootstage;
+		struct bootstage_record *rec;
+		int i;
+
+		for (rec = data->record, i = 0; i < data->rec_count; i++, rec++)
+			size += strlen(rec->name) + 1;
+	}
 
 	return size;
 }

common/dlmalloc.c

@@ -16,6 +16,8 @@
 #include <asm/global_data.h>
 
 #include <malloc.h>
+#include <mapmem.h>
+#include <string.h>
 #include <asm/io.h>
 #include <valgrind/memcheck.h>
 
@@ -598,9 +600,9 @@ void *sbrk(ptrdiff_t increment)
 
 void mem_malloc_init(ulong start, ulong size)
 {
-	mem_malloc_start = start;
-	mem_malloc_end = start + size;
-	mem_malloc_brk = start;
+	mem_malloc_start = (ulong)map_sysmem(start, size);
+	mem_malloc_end = mem_malloc_start + size;
+	mem_malloc_brk = mem_malloc_start;
 
 #ifdef CONFIG_SYS_MALLOC_DEFAULT_TO_INIT
 	malloc_init();

common/spl/spl.c

@@ -678,9 +678,7 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
 	spl_set_bd();
 
 	if (IS_ENABLED(CONFIG_SPL_SYS_MALLOC)) {
-		mem_malloc_init((ulong)map_sysmem(SPL_SYS_MALLOC_START,
-						  SPL_SYS_MALLOC_SIZE),
-				SPL_SYS_MALLOC_SIZE);
+		mem_malloc_init(SPL_SYS_MALLOC_START, SPL_SYS_MALLOC_SIZE);
 		gd->flags |= GD_FLG_FULL_MALLOC_INIT;
 	}
 	if (!(gd->flags & GD_FLG_SPL_INIT)) {

doc/usage/cmd/meminfo.rst

@@ -0,0 +1,128 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+.. index::
+   single: meminfo (command)
+
+meminfo command
+===============
+
+Synopsis
+--------
+
+::
+
+    meminfo
+
+Description
+-----------
+
+The meminfo command shows the amount of memory. If ``CONFIG_CMD_MEMINFO_MAP`` is
+enabled, then it also shows the layout of memory used by U-Boot and the region
+which is free for use by images.
+
+The layout of memory is set up before relocation, within the init sequence in
+``board_init_f()``, specifically the various ``reserve_...()`` functions. This
+'reservation' of memory starts from the top of RAM and proceeds downwards,
+ending with the stack. This results in the maximum possible amount of memory
+being left free for image-loading.
+
+The meminfo command writes the DRAM size, then the rest of its outputs in 5
+columns:
+
+Region
+   Name of the region
+
+Base
+    Base address of the region, i.e. where it starts in memory
+
+Size
+    Size of the region, which may be a little smaller than the actual size
+    reserved, e.g. due to alignment
+
+End
+    End of the region. The last byte of the region is one lower than the address
+    shown here
+
+Gap
+    Gap between the end of this region and the base of the one above
+
+Regions shown are:
+
+video
+    Memory reserved for video framebuffers. This reservation happens in the
+    bind() methods of all video drivers which are present before relocation,
+    so the size depends on that maximum amount of memory which all such drivers
+    want to reserve. This may be significantly greater than the amount actually
+    needed, if the display is ultimately set to a smaller resolution or colour
+    depth than the maximum supported.
+
+code
+    U-Boot's code and Block-Starting Symbol (BSS) region. Before relocation,
+    U-Boot copies its code to a high region and sets up a BSS immediately after
+    that. The size of this region is generally therefore ``__bss_end`` -
+    ``__image_copy_start``
+
+malloc
+    Contains the malloc() heap. The size of this is set by
+    ``CONFIG_SYS_MALLOC_LEN``.
+
+board_info
+    Contains the ``bd_info`` structure, with some information about the current
+    board.
+
+global_data
+    Contains the global-data structure, pointed to by ``gd``. This includes
+    various pointers, values and flags which control U-Boot.
+
+devicetree
+    Contains the flatted devicetree blob (FDT) being used by U-Boot to configure
+    itself and its devices.
+
+bootstage
+    Contains the bootstage records, which keep track of boot time as U-Boot
+    executes. The size of this is determined by
+    ``CONFIG_BOOTSTAGE_RECORD_COUNT``, with each record taking approximately
+    32 bytes.
+
+bloblist
+    Contains the bloblist, which is a list of tables and other data created by
+    U-Boot while executed. The size of this is determined by
+    ``CONFIG_BLOBLIST_SIZE``.
+
+stack
+    Contains U-Boot's stack, growing downwards from the top. The nominal size of
+    this region is set by ``CONFIG_STACK_SIZE`` but there is no actual limit
+    enforced, so the stack can grow behind that. Images should be loaded lower
+    in memory to avoid any conflict.
+
+free
+    Free memory, which is available for loading images. The base address of
+    this is ``gd->ram_base`` which is generally set by ``CFG_SYS_SDRAM_BASE``.
+
+Example
+-------
+
+This example shows output with both ``CONFIG_CMD_MEMINFO`` and
+``CONFIG_CMD_MEMINFO_MAP`` enabled::
+
+    => meminfo
+    DRAM:  256 MiB
+
+    Region           Base     Size      End      Gap
+    ------------------------------------------------
+    video         f000000  1000000 10000000
+    code          ec3a000   3c5d28  efffd28      2d8
+    malloc        8c38000  6002000  ec3a000        0
+    board_info    8c37f90       68  8c37ff8        8
+    global_data   8c37d80      208  8c37f88        8
+    devicetree    8c33000     4d7d  8c37d7d        3
+    bootstage     8c32c20      3c8  8c32fe8       18
+    bloblist      8c32000      400  8c32400      820
+    stack         7c31ff0  1000000  8c31ff0       10
+    free                0  7c31ff0  7c31ff0        0
+
+
+Return value
+------------
+
+The return value $? is always 0 (true).

doc/usage/index.rst

@@ -84,6 +84,7 @@ Shell commands
    cmd/loads
    cmd/loadx
    cmd/loady
+   cmd/meminfo
    cmd/mbr
    cmd/md
    cmd/mmc

include/asm-generic/global_data.h

@@ -543,6 +543,36 @@ static_assert(sizeof(struct global_data) == GD_SIZE);
 #define gd_set_upl(val)
 #endif
 
+#if CONFIG_IS_ENABLED(BLOBLIST)
+#define gd_bloblist()		gd->bloblist
+#else
+#define gd_bloblist()		NULL
+#endif
+
+#if CONFIG_IS_ENABLED(BOOTSTAGE)
+#define gd_bootstage()		gd->bootstage
+#else
+#define gd_bootstage()		NULL
+#endif
+
+#if CONFIG_IS_ENABLED(TRACE)
+#define gd_trace_buff()		gd->trace_buff
+#define gd_trace_size()		CONFIG_TRACE_BUFFER_SIZE
+#else
+#define gd_trace_buff()		NULL
+#define gd_trace_size()		0
+#endif
+
+#if CONFIG_IS_ENABLED(VIDEO)
+#define gd_video_top()		gd->video_top
+#define gd_video_bottom()	gd->video_bottom
+#define gd_video_size()		(gd->video_top - gd->video_bottom)
+#else
+#define gd_video_top()		0
+#define gd_video_bottom()	0
+#define gd_video_size()		0
+#endif
+
 /**
  * enum gd_flags - global data flags
  *

include/bootstage.h

@@ -371,9 +371,10 @@ int bootstage_unstash(const void *base, int size);
 /**
  * bootstage_get_size() - Get the size of the bootstage data
  *
+ * @add_strings: true to add the size of attached strings (for stashing)
  * Return: size of boostage data in bytes
  */
-int bootstage_get_size(void);
+int bootstage_get_size(bool add_strings);
 
 /**
  * bootstage_init() - Prepare bootstage for use
@@ -444,7 +445,7 @@ static inline int bootstage_unstash(const void *base, int size)
 	return 0;	/* Pretend to succeed */
 }
 
-static inline int bootstage_get_size(void)
+static inline int bootstage_get_size(bool add_strings)
 {
 	return 0;
 }

include/malloc.h

@@ -981,6 +981,14 @@ extern ulong mem_malloc_start;
 extern ulong mem_malloc_end;
 extern ulong mem_malloc_brk;
 
+/**
+ * mem_malloc_init() - Set up the malloc() pool
+ *
+ * Sets the region of memory to be used for all future calls to malloc(), etc.
+ *
+ * @start: Start address
+ * @size: Size in bytes
+ */
 void mem_malloc_init(ulong start, ulong size);
 
 #ifdef __cplusplus

lib/lmb.c

@@ -887,12 +887,12 @@ int lmb_init(void)
 	return 0;
 }
 
-#if CONFIG_IS_ENABLED(UNIT_TEST)
 struct lmb *lmb_get(void)
 {
 	return &lmb;
 }
 
+#if CONFIG_IS_ENABLED(UNIT_TEST)
 int lmb_push(struct lmb *store)
 {
 	int ret;

test/cmd/Makefile

@@ -19,8 +19,9 @@ obj-$(CONFIG_CMD_FDT) += fdt.o
 obj-$(CONFIG_CONSOLE_TRUETYPE) += font.o
 obj-$(CONFIG_CMD_HISTORY) += history.o
 obj-$(CONFIG_CMD_LOADM) += loadm.o
-obj-$(CONFIG_CMD_MEM_SEARCH) += mem_search.o
+obj-$(CONFIG_CMD_MEMINFO) += meminfo.o
 obj-$(CONFIG_CMD_MEMORY) += mem_copy.o
+obj-$(CONFIG_CMD_MEM_SEARCH) += mem_search.o
 ifdef CONFIG_CMD_PCI
 obj-$(CONFIG_CMD_PCI_MPS) += pci_mps.o
 endif

test/cmd/meminfo.c

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test for 'meminfo' command
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <dm/test.h>
+#include <test/cmd.h>
+#include <test/ut.h>
+
+/* Test 'meminfo' command */
+static int cmd_test_meminfo(struct unit_test_state *uts)
+{
+	ut_assertok(run_command("meminfo", 0));
+	ut_assert_nextline("DRAM:  256 MiB");
+	ut_assert_nextline_empty();
+
+	ut_assert_nextline("Region           Base     Size      End      Gap");
+	ut_assert_nextlinen("-");
+
+	/* For now we don't worry about checking the values */
+	ut_assert_nextlinen("video");
+	ut_assert_nextlinen("code");
+	ut_assert_nextlinen("malloc");
+	ut_assert_nextlinen("board_info");
+	ut_assert_nextlinen("global_data");
+	ut_assert_nextlinen("devicetree");
+	ut_assert_nextlinen("bootstage");
+	ut_assert_nextlinen("bloblist");
+	ut_assert_nextlinen("stack");
+
+	/* we expect at least one lmb line, but don't know how many */
+	ut_assert_nextlinen("lmb");
+	ut_assert_skip_to_linen("free");
+
+	ut_assert_console_end();
+
+	return 0;
+}
+CMD_TEST(cmd_test_meminfo, UTF_CONSOLE);