[PATCH v2 1/1] efi_loader: print device-tree in dtbdump.efi
Heinrich Schuchardt
heinrich.schuchardt at canonical.com
Sat Jun 29 09:00:46 CEST 2024
The dtbdump.efi binary can be used for testing the EFI_DT_FIXUP_PROTOCOL.
It provides a command to load a file and have it fixed up and a
command to save the resulting file.
Add a command 'dump' for displaying the device-tree.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
v2:
print leading '/dts-v1/;'
print memory reservation block
allow space in string property value to match dtc logic
correct formatting of byte strings
---
lib/efi_loader/dtbdump.c | 261 +++++++++++++++++++++++++++++++++++++++
1 file changed, 261 insertions(+)
diff --git a/lib/efi_loader/dtbdump.c b/lib/efi_loader/dtbdump.c
index 5f39cf22da7..116593d9e25 100644
--- a/lib/efi_loader/dtbdump.c
+++ b/lib/efi_loader/dtbdump.c
@@ -40,6 +40,53 @@ static void print(u16 *string)
cout->output_string(cout, string);
}
+/**
+ * print_char() - print character
+ *
+ * 0x00 is replaced by '", "'.
+ *
+ * @c: - character
+ */
+static void print_char(unsigned char c)
+{
+ u16 out[2] = u"?";
+
+ if (!c) {
+ print(u"\", \"");
+ return;
+ }
+
+ if (c > 0x1f && c < 0x80)
+ out[0] = c;
+
+ print(out);
+}
+
+/**
+ * print_hex_digit() - print hexadecimal digit
+ *
+ * @digit: digit to print
+ */
+static void print_hex_digit(unsigned char digit)
+{
+ if (digit < 10)
+ digit += '0';
+ else
+ digit += 'a' - 10;
+ print_char(digit);
+}
+
+/**
+ * printx() - print hexadecimal byte
+ *
+ * @val: value to print
+ */
+static void printx(unsigned char val)
+{
+ print_hex_digit(val >> 4);
+ print_hex_digit(val & 0xf);
+}
+
/**
* error() - print error string
*
@@ -227,6 +274,7 @@ bool starts_with(u16 *string, u16 *keyword)
*/
void do_help(void)
{
+ error(u"dump - print device-tree\r\n");
error(u"load <dtb> - load device-tree from file\r\n");
error(u"save <dtb> - save device-tree to file\r\n");
error(u"exit - exit the shell\r\n");
@@ -489,6 +537,217 @@ efi_status_t do_save(u16 *filename)
return ret;
}
+/**
+ * indent() - print a number of tabstops
+ *
+ * @level: indentation level
+ */
+static void indent(u32 level)
+{
+ for (; level; --level)
+ print(u"\t");
+}
+
+/**
+ * is_string_value() - determine if property is a string
+ *
+ * If a property is a string, an x-string, or a u32 cannot be deducted
+ * from the device-tree. Therefore a heuristic is used.
+ *
+ * @str: pointer to device-tree property
+ * @len: length of the device-tree property
+ * Return: 1 for string, 0 otherwise
+ */
+static int is_string_value(const unsigned char *str, u32 len)
+{
+ int nonzero_flag = 0;
+
+ /* Zero length or not ending with 0x00 */
+ if (!len || str[len - 1])
+ return 0;
+
+ for (u32 i = 0; i < len; ++i) {
+ if (!str[i]) {
+ /* Zero length string or two consecutive 0x00 */
+ if (!nonzero_flag)
+ return 0;
+
+ nonzero_flag = 0;
+
+ continue;
+ }
+ /* Non-printable */
+ if (str[i] < 0x20 || str[i] >= 0x80)
+ return 0;
+
+ nonzero_flag = 1;
+ }
+
+ return 1;
+}
+
+/**
+ * print_property() - print device-tree property
+ *
+ * If a property is a string, an x-string, or a u32 cannot be deducted
+ * from the device-tree. Therefore a heuristic is used.
+ *
+ * @str: property value
+ * @len: length of property value
+ */
+static void print_property(const unsigned char *val, u32 len)
+{
+ if (is_string_value(val, len)) {
+ /* string */
+ print(u"\"");
+ for (int i = 0; i < len - 1; ++i)
+ print_char(val[i]);
+ print(u"\"");
+ } else if (len & 0x3) {
+ /* byte string */
+ print(u"[");
+ for (int i = 0; i < len; ++i) {
+ if (i)
+ print(u" ");
+ printx(val[i]);
+ }
+ print(u"]\"");
+ } else {
+ /* cell list */
+ print(u"<");
+ for (u32 i = 0; i < len; ++i) {
+ if ((i & 0x3) == 0) {
+ if (i > 0)
+ print(u" ");
+ print(u"0x");
+ }
+ printx(val[i]);
+ }
+ print(u">");
+ }
+}
+
+/**
+ * print_mem_res_block() - print memory reservation block
+ *
+ * @rsvblk: memory reservation block
+ */
+static void print_mem_res_block(const struct fdt_reserve_entry *rsvblk)
+{
+ for (; rsvblk->address || rsvblk->size; ++rsvblk) {
+ const unsigned char *val;
+
+ print(u"/memreserve/ 0x");
+ val = (const unsigned char *)&rsvblk->address;
+ for (u32 i = 0; i < sizeof(u64); ++i)
+ printx(val[i]);
+ print(u" 0x");
+ val = (const unsigned char *)&rsvblk->size;
+ for (u32 i = 0; i < sizeof(u64); ++i)
+ printx(val[i]);
+ print(u";\r\n");
+ }
+}
+
+/**
+ * do_dump() - print device-tree
+ */
+static efi_status_t do_dump(void)
+{
+ const unsigned char *fdt;
+ struct fdt_header *header;
+ const u32 *end;
+ const u32 *pos;
+ const char *strings;
+ u32 level = 0;
+
+ fdt = get_dtb(systable);
+ if (!fdt) {
+ error(u"DTB not found\r\n");
+ return EFI_NOT_FOUND;
+ }
+
+ header = (struct fdt_header *)fdt;
+ if (f2h(header->magic) != FDT_MAGIC) {
+ error(u"Wrong device tree magic\r\n");
+ error(u"Not a device-tree\r\n");
+ return EFI_LOAD_ERROR;
+ }
+
+ pos = (u32 *)(fdt + f2h(header->off_dt_struct));
+ end = &pos[f2h(header->totalsize) >> 2];
+ strings = fdt + f2h(header->off_dt_strings);
+
+ print(u"/dts-v1/;\r\n");
+
+ print_mem_res_block((const struct fdt_reserve_entry *)
+ (fdt + f2h(header->off_mem_rsvmap)));
+
+ print(u"/");
+ for (; pos < end;) {
+ switch (f2h(pos[0])) {
+ case FDT_BEGIN_NODE: {
+ const char *c = (char *)&pos[1];
+ size_t i;
+
+ indent(level);
+ for (i = 0; c[i]; ++i)
+ print_char(c[i]);
+ print(u" {\n\r");
+
+ ++level;
+ pos = &pos[2 + (i >> 2)];
+ break;
+ }
+ case FDT_PROP: {
+ struct fdt_property *prop = (struct fdt_property *)pos;
+ const unsigned char *label = &strings[f2h(prop->nameoff)];
+ u32 len = f2h(prop->len);
+ const unsigned char *str = (unsigned char *)&pos[3];
+
+ indent(level);
+ for (int i = 0; label[i]; ++i)
+ print_char(label[i]);
+
+ if (len) {
+ print(u" = ");
+ print_property(str, len);
+ }
+ print(u";\r\n");
+
+ pos = &pos[3 + ((f2h(prop->len) + 3) >> 2)];
+ break;
+ }
+ case FDT_NOP:
+ ++pos;
+ break;
+ case FDT_END_NODE:
+ if (!level) {
+ error(u"Extraneous end node\r\n");
+ return EFI_LOAD_ERROR;
+ }
+
+ --level;
+ indent(level);
+ print(u"};\n\r");
+ ++pos;
+ break;
+ case FDT_END:
+ if (level) {
+ error(u"Missing end node\r\n");
+ return EFI_LOAD_ERROR;
+ }
+ return EFI_SUCCESS;
+ default:
+ error(u"Invalid device tree token\r\n");
+ return EFI_LOAD_ERROR;
+ }
+ }
+ error(u"Overrun\r\n");
+
+ return EFI_LOAD_ERROR;
+}
+
/**
* efi_main() - entry point of the EFI application.
*
@@ -524,6 +783,8 @@ efi_status_t EFIAPI efi_main(efi_handle_t image_handle,
pos = skip_whitespace(command);
if (starts_with(pos, u"exit"))
break;
+ else if (starts_with(pos, u"dump"))
+ do_dump();
else if (starts_with(pos, u"load "))
do_load(pos + 5);
else if (starts_with(pos, u"save "))
--
2.45.2
More information about the U-Boot
mailing list