U-Boot has a fairly rigid memory map which is normally not visible
unless debugging is enabled in board_f.c
Add a 'memmap' command which shows it. This command does not cover
arch-specific pieces but gives a good overview of where things are.
Signed-off-by: Simon Glass <s...@chromium.org>
---
cmd/Kconfig | 10 ++++
cmd/Makefile | 1 +
cmd/memmap.c | 66 +++++++++++++++++++++
doc/usage/cmd/memmap.rst | 123 +++++++++++++++++++++++++++++++++++++++
doc/usage/index.rst | 1 +
test/cmd/Makefile | 3 +-
test/cmd/memmap.c | 35 +++++++++++
7 files changed, 238 insertions(+), 1 deletion(-)
create mode 100644 cmd/memmap.c
create mode 100644 doc/usage/cmd/memmap.rst
create mode 100644 test/cmd/memmap.c
diff --git a/cmd/Kconfig b/cmd/Kconfig
index dd33266cec7..d4a29217323 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -921,6 +921,16 @@ config CMD_MEM_SEARCH
pressing return will show the next 10 matches. Environment variables
are set for use with scripting (memmatches, memaddr, mempos).
+config CMD_MEMMAP
+ bool "memmap - Memory map"
+ default y if SANDBOX
+ help
+ memmap command
+
+ This shows the location of areas of memory used by U-Boot. This
includes
+ the malloc() region, U-Boot's code and data, bloblist and anything
else
+ that prevents a particular region being used for loading images.
+
config CMD_MX_CYCLIC
bool "Enable cyclic md/mw commands"
depends on CMD_MEMORY
diff --git a/cmd/Makefile b/cmd/Makefile
index 91227f1249c..4f05dafaaad 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -109,6 +109,7 @@ obj-y += load.o
obj-$(CONFIG_CMD_LOG) += log.o
obj-$(CONFIG_CMD_LSBLK) += lsblk.o
obj-$(CONFIG_CMD_MD5SUM) += md5sum.o
+obj-$(CONFIG_CMD_MEMMAP) += memmap.o
obj-$(CONFIG_CMD_MEMORY) += mem.o
obj-$(CONFIG_CMD_IO) += io.o
obj-$(CONFIG_CMD_MII) += mii.o
diff --git a/cmd/memmap.c b/cmd/memmap.c
new file mode 100644
index 00000000000..d83c04467e9
--- /dev/null
+++ b/cmd/memmap.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <s...@chromium.org>
+ */
+
+#include <bloblist.h>
+#include <bootstage.h>
+#include <command.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 int do_memmap(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ ulong upto, stk_bot;
+
+ printf("%-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", 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(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);
+ print_region("free", gd->ram_base, stk_bot, &upto);
+
+ return 0;
+}
+
+U_BOOT_CMD(
+ memmap, 1, 1, do_memmap, "Show a map of U-Boot's memory usage", ""
+);
diff --git a/doc/usage/cmd/memmap.rst b/doc/usage/cmd/memmap.rst
new file mode 100644
index 00000000000..2f0888a9691
--- /dev/null
+++ b/doc/usage/cmd/memmap.rst
@@ -0,0 +1,123 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+.. index::
+ single: memmap (command)
+
+memmap command
+==============
+
+Synopsis
+--------
+
+::
+
+ memmap
+
+Description
+-----------
+
+The memmap command 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 memmap command writes 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
+-------
+
+::
+
+ => memmap
+ 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 $? is always 0 (true).
diff --git a/doc/usage/index.rst b/doc/usage/index.rst
index 70563374899..dd2b5807a4f 100644
--- a/doc/usage/index.rst
+++ b/doc/usage/index.rst
@@ -83,6 +83,7 @@ Shell commands
cmd/loads
cmd/loadx
cmd/loady
+ cmd/memmap
cmd/mbr
cmd/md
cmd/mmc
diff --git a/test/cmd/Makefile b/test/cmd/Makefile
index 8f2134998ad..3f6ae59f3d4 100644
--- a/test/cmd/Makefile
+++ b/test/cmd/Makefile
@@ -18,8 +18,9 @@ obj-$(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-$(CONFIG_CMD_MEMMAP) += memmap.o
obj-$(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
diff --git a/test/cmd/memmap.c b/test/cmd/memmap.c
new file mode 100644
index 00000000000..f12d7174838
--- /dev/null
+++ b/test/cmd/memmap.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test for 'memmap' command
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <s...@chromium.org>
+ */
+
+#include <dm/test.h>
+#include <test/cmd.h>
+#include <test/ut.h>
+
+/* Test 'memmap' command */
+static int cmd_test_memmap(struct unit_test_state *uts)
+{
+ ut_assertok(run_command("memmap", 0));
+ 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");
+ ut_assert_nextlinen("free");
+ ut_assert_console_end();
+
+ return 0;
+}
+CMD_TEST(cmd_test_memmap, UTF_CONSOLE);
--
2.43.0
