The QMP/HMP 'dumpdtb' command is saving the FDT blob to be decoded using
'dtc' like the '-machine dumpdtb' always did. However, after adding
support for the 'info fdt' command, we're now able to format a full FDT
in text format - which is what 'info fdt /' already does.
Let's extend the 'dumpdtb' QMP/HMP command with the capability of saving
the FDT in plain text format. A new textformat '-t' option was added to
it. With this option, qemu_fdt_qmp_dumpdtb() will call
qemu_fdt_qmp_query_fdt() to retrieve the human string that represents
the output of 'info fdt /' and write it to the file.
This will allow users to dump the FDT in a text file and immediately
open it to see its contents, without the need of an extra step to decode
a dtb blob with 'dtc'. Here's an example:
(qemu) dumpdtb fdt.dtb
$ file fdt.dtb
fdt.dtb: Device Tree Blob version 17, size=15458, boot CPU=0, string block
size=2318, DT structure block size=13084
(qemu) dumpdtb -t fdt.txt
$ file fdt.txt
fdt.txt: ASCII text, with very long lines (4746)
$ grep -A 3 'persistent-memory' fdt.txt
ibm,persistent-memory {
device_type = "ibm,persistent-memory";
#size-cells = <0x0>;
#address-cells = <0x1>;
};
Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com>
---
hmp-commands.hx | 7 ++++---
include/sysemu/device_tree.h | 3 ++-
monitor/hmp-cmds.c | 3 ++-
monitor/qmp-cmds.c | 8 +++++---
qapi/machine.json | 2 +-
softmmu/device_tree.c | 25 ++++++++++++++++++++++---
6 files changed, 36 insertions(+), 12 deletions(-)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 2dd737078e..8a9595cc26 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1808,8 +1808,9 @@ SRST
ERST
{
.name = "dumpdtb",
- .args_type = "filename:F",
- .params = "filename",
- .help = "save the FDT in the 'filename' file to be decoded using
dtc",
+ .args_type = "textformat:-t,filename:F",
+ .params = "[-t] filename",
+ .help = "save the FDT in the 'filename' file to be decoded using
dtc."
+ "Use '-t' to save the file in text (dts) format.",
.cmd = hmp_dumpdtb,
},
diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h
index 551a02dee2..082ff69751 100644
--- a/include/sysemu/device_tree.h
+++ b/include/sysemu/device_tree.h
@@ -138,7 +138,8 @@ int qemu_fdt_add_path(void *fdt, const char *path);
} while (0)
void qemu_fdt_dumpdtb(void *fdt, int size);
-void qemu_fdt_qmp_dumpdtb(const char *filename, Error **errp);
+void qemu_fdt_qmp_dumpdtb(const char *filename, bool textformat,
+ Error **errp);
HumanReadableText *qemu_fdt_qmp_query_fdt(const char *nodepath,
bool has_propname,
const char *propname,
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 320204e982..ffcb9ffb67 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -2476,9 +2476,10 @@ exit_no_print:
void hmp_dumpdtb(Monitor *mon, const QDict *qdict)
{
const char *filename = qdict_get_str(qdict, "filename");
+ bool textformat = qdict_get_try_bool(qdict, "textformat", false);
Error *local_err = NULL;
- qmp_dumpdtb(filename, &local_err);
+ qmp_dumpdtb(true, textformat, filename, &local_err);
if (local_err) {
hmp_handle_error(mon, local_err);
diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
index ca2a96cdf7..8d625e5e7d 100644
--- a/monitor/qmp-cmds.c
+++ b/monitor/qmp-cmds.c
@@ -599,9 +599,10 @@ bool apply_str_list_filter(const char *string, strList
*list)
}
#ifdef CONFIG_FDT
-void qmp_dumpdtb(const char *filename, Error **errp)
+void qmp_dumpdtb(bool has_textformat, bool textformat,
+ const char *filename, Error **errp)
{
- return qemu_fdt_qmp_dumpdtb(filename, errp);
+ return qemu_fdt_qmp_dumpdtb(filename, textformat, errp);
}
HumanReadableText *qmp_x_query_fdt(const char *nodepath, bool has_propname,
@@ -610,7 +611,8 @@ HumanReadableText *qmp_x_query_fdt(const char *nodepath,
bool has_propname,
return qemu_fdt_qmp_query_fdt(nodepath, has_propname, propname, errp);
}
#else
-void qmp_dumpdtb(const char *filename, Error **errp)
+void qmp_dumpdtb(bool has_textformat, bool textformat,
+ const char *filename, Error **errp)
{
error_setg(errp, "dumpdtb requires libfdt");
}
diff --git a/qapi/machine.json b/qapi/machine.json
index c15ce60f46..8573f96da8 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -1680,7 +1680,7 @@
#
##
{ 'command': 'dumpdtb',
- 'data': { 'filename': 'str' } }
+ 'data': { '*textformat':'bool', 'filename': 'str' } }
##
# @x-query-fdt:
diff --git a/softmmu/device_tree.c b/softmmu/device_tree.c
index ad2386295b..34af31552d 100644
--- a/softmmu/device_tree.c
+++ b/softmmu/device_tree.c
@@ -645,8 +645,10 @@ out:
return ret;
}
-void qemu_fdt_qmp_dumpdtb(const char *filename, Error **errp)
+void qemu_fdt_qmp_dumpdtb(const char *filename, bool textformat, Error **errp)
{
+ g_autoptr(HumanReadableText) txt = NULL;
+ void *contents = NULL;
int size;
if (!current_machine->fdt) {
@@ -654,9 +656,26 @@ void qemu_fdt_qmp_dumpdtb(const char *filename, Error
**errp)
return;
}
- size = fdt_totalsize(current_machine->fdt);
+ if (textformat) {
+ /*
+ * 'info fdt /' returns all the FDT in text format, formatted
+ * with a style close to what 'dtc' uses to decode the blob
+ * to a .dts.
+ */
+ txt = qemu_fdt_qmp_query_fdt("/", false, NULL, errp);
+
+ if (!txt) {
+ return;
+ }
+
+ contents = txt->human_readable_text;
+ size = strlen(txt->human_readable_text);
+ } else {
+ contents = current_machine->fdt;
+ size = fdt_totalsize(current_machine->fdt);
+ }
- if (g_file_set_contents(filename, current_machine->fdt, size, NULL)) {
+ if (g_file_set_contents(filename, contents, size, NULL)) {
return;
}
--
2.37.2
