[PATCH v6 1/3] cmd: mem: add command for getting ram size for use in scripts
Frank Wunderlich
linux at fw-web.de
Sun Jan 25 14:12:51 CET 2026
From: Frank Wunderlich <frank-w at public-files.de>
Add a command for getting detected ram size with possibility to
assign it to an environment variable.
example usage:
BPI-R4> memsize
4096 MiB
BPI-R4> memsize memsz
BPI-R4> printenv memsz
memsz=4096
BPI-R4>
board with 8GB ram:
BPI-R4> memsize
8192 MiB
BPI-R4> memsize memsz
BPI-R4> printenv memsz
memsz=8192
BPI-R4>
Signed-off-by: Frank Wunderlich <frank-w at public-files.de>
---
v6: add missing return for error in env_set_ulong
v5: move msize to meminfo and drop first param (always display as MiB)
rename msize to memsize
v4: drop rounding to full MB/GB as it leads to wrong display
v3: add missing ifdefs
v2: add Kconfig entry
---
cmd/Kconfig | 6 ++++++
cmd/meminfo.c | 25 +++++++++++++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 5c611fb3016e..be79bf0747df 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -925,6 +925,12 @@ config CMD_MEMINFO_MAP
See doc/usage/cmd/meminfo.rst for more information.
+config CMD_MEMSIZE
+ bool "memsize"
+ depends on CMD_MEMINFO
+ help
+ Get RAM via command for use in scripts.
+
config CMD_MEMORY
bool "md, mm, nm, mw, cp, cmp, base, loop"
default y
diff --git a/cmd/meminfo.c b/cmd/meminfo.c
index aa3b5bafe176..e7db9d065f5a 100644
--- a/cmd/meminfo.c
+++ b/cmd/meminfo.c
@@ -8,10 +8,12 @@
#include <bootstage.h>
#include <command.h>
#include <display_options.h>
+#include <env.h>
#include <lmb.h>
#include <malloc.h>
#include <mapmem.h>
#include <asm/global_data.h>
+#include <linux/sizes.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -98,8 +100,31 @@ static int do_meminfo(struct cmd_tbl *cmdtp, int flag, int argc,
return 0;
}
+#ifdef CONFIG_CMD_MEMSIZE
+static int do_mem_size(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ u64 memsize = gd->ram_size / SZ_1M;
+
+ if (argc > 1)
+ return env_set_ulong(argv[1], memsize);
+ else
+ printf("%lld MiB\n", memsize);
+
+ return 0;
+}
+#endif /* CONFIG_CMD_MEMSIZE */
+
U_BOOT_CMD(
meminfo, 1, 1, do_meminfo,
"display memory information",
""
);
+
+#ifdef CONFIG_CMD_MEMSIZE
+U_BOOT_CMD(
+ memsize, 2, 1, do_mem_size,
+ "get detected ram size in MiB, optional set env variable with value",
+ "[envvar]"
+);
+#endif /* CONFIG_CMD_MEMSIZE */
--
2.43.0
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