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Diffstat (limited to 'arch/arm/boot/compressed/atags_to_fdt.c')
-rw-r--r--arch/arm/boot/compressed/atags_to_fdt.c62
1 files changed, 60 insertions, 2 deletions
diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c
index 797f04bedb4..aabc02a6848 100644
--- a/arch/arm/boot/compressed/atags_to_fdt.c
+++ b/arch/arm/boot/compressed/atags_to_fdt.c
@@ -1,6 +1,12 @@
#include <asm/setup.h>
#include <libfdt.h>
+#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
+#define do_extend_cmdline 1
+#else
+#define do_extend_cmdline 0
+#endif
+
static int node_offset(void *fdt, const char *node_path)
{
int offset = fdt_path_offset(fdt, node_path);
@@ -36,6 +42,48 @@ static int setprop_cell(void *fdt, const char *node_path,
return fdt_setprop_cell(fdt, offset, property, val);
}
+static const void *getprop(const void *fdt, const char *node_path,
+ const char *property, int *len)
+{
+ int offset = fdt_path_offset(fdt, node_path);
+
+ if (offset == -FDT_ERR_NOTFOUND)
+ return NULL;
+
+ return fdt_getprop(fdt, offset, property, len);
+}
+
+static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
+{
+ char cmdline[COMMAND_LINE_SIZE];
+ const char *fdt_bootargs;
+ char *ptr = cmdline;
+ int len = 0;
+
+ /* copy the fdt command line into the buffer */
+ fdt_bootargs = getprop(fdt, "/chosen", "bootargs", &len);
+ if (fdt_bootargs)
+ if (len < COMMAND_LINE_SIZE) {
+ memcpy(ptr, fdt_bootargs, len);
+ /* len is the length of the string
+ * including the NULL terminator */
+ ptr += len - 1;
+ }
+
+ /* and append the ATAG_CMDLINE */
+ if (fdt_cmdline) {
+ len = strlen(fdt_cmdline);
+ if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
+ *ptr++ = ' ';
+ memcpy(ptr, fdt_cmdline, len);
+ ptr += len;
+ }
+ }
+ *ptr = '\0';
+
+ setprop_string(fdt, "/chosen", "bootargs", cmdline);
+}
+
/*
* Convert and fold provided ATAGs into the provided FDT.
*
@@ -72,8 +120,18 @@ int atags_to_fdt(void *atag_list, void *fdt, int total_space)
for_each_tag(atag, atag_list) {
if (atag->hdr.tag == ATAG_CMDLINE) {
- setprop_string(fdt, "/chosen", "bootargs",
- atag->u.cmdline.cmdline);
+ /* Append the ATAGS command line to the device tree
+ * command line.
+ * NB: This means that if the same parameter is set in
+ * the device tree and in the tags, the one from the
+ * tags will be chosen.
+ */
+ if (do_extend_cmdline)
+ merge_fdt_bootargs(fdt,
+ atag->u.cmdline.cmdline);
+ else
+ setprop_string(fdt, "/chosen", "bootargs",
+ atag->u.cmdline.cmdline);
} else if (atag->hdr.tag == ATAG_MEM) {
if (memcount >= sizeof(mem_reg_property)/4)
continue;