Add uboot "fdt_high" enviroment variable
Add a new "fdt_high" enviroment variable. This can be used to control (or prevent) the
relocation of the flattened device tree on boot. It can be used to prevent relocation
of the fdt into highmem. The variable behaves similarly to the existing "initrd_high"
variable.
Signed-off-by: David A. Long <dave.long@linaro.org>
diff --git a/common/image.c b/common/image.c
index e542a57..c6cd85e 100644
--- a/common/image.c
+++ b/common/image.c
@@ -1234,8 +1234,10 @@
{
void *fdt_blob = *of_flat_tree;
void *of_start = 0;
+ char *fdt_high;
ulong of_len = 0;
int err;
+ int disable_relocation = 0;
/* nothing to do */
if (*of_size == 0)
@@ -1249,26 +1251,62 @@
/* position on a 4K boundary before the alloc_current */
/* Pad the FDT by a specified amount */
of_len = *of_size + CONFIG_SYS_FDT_PAD;
- of_start = (void *)(unsigned long)lmb_alloc_base(lmb, of_len, 0x1000,
- getenv_bootm_mapsize() + getenv_bootm_low());
+
+ /* If fdt_high is set use it to select the relocation address */
+ fdt_high = getenv("fdt_high");
+ if (fdt_high) {
+ void *desired_addr = (void *)simple_strtoul(fdt_high, NULL, 16);
+
+ if (((ulong) desired_addr) == ~0UL) {
+ /* All ones means use fdt in place */
+ desired_addr = fdt_blob;
+ disable_relocation = 1;
+ }
+ if (desired_addr) {
+ of_start =
+ (void *)(ulong) lmb_alloc_base(lmb, of_len, 0x1000,
+ ((ulong)
+ desired_addr)
+ + of_len);
+ if (desired_addr && of_start != desired_addr) {
+ puts("Failed using fdt_high value for Device Tree");
+ goto error;
+ }
+ } else {
+ of_start =
+ (void *)(ulong) mb_alloc(lmb, of_len, 0x1000);
+ }
+ } else {
+ of_start =
+ (void *)(ulong) lmb_alloc_base(lmb, of_len, 0x1000,
+ getenv_bootm_mapsize()
+ + getenv_bootm_low());
+ }
if (of_start == 0) {
puts("device tree - allocation error\n");
goto error;
}
- debug ("## device tree at %p ... %p (len=%ld [0x%lX])\n",
- fdt_blob, fdt_blob + *of_size - 1, of_len, of_len);
+ if (disable_relocation) {
+ /* We assume there is space after the existing fdt to use for padding */
+ fdt_set_totalsize(of_start, of_len);
+ printf(" Using Device Tree in place at %p, end %p\n",
+ of_start, of_start + of_len - 1);
+ } else {
+ debug ("## device tree at %p ... %p (len=%ld [0x%lX])\n",
+ fdt_blob, fdt_blob + *of_size - 1, of_len, of_len);
- printf (" Loading Device Tree to %p, end %p ... ",
- of_start, of_start + of_len - 1);
+ printf (" Loading Device Tree to %p, end %p ... ",
+ of_start, of_start + of_len - 1);
- err = fdt_open_into (fdt_blob, of_start, of_len);
- if (err != 0) {
- fdt_error ("fdt move failed");
- goto error;
+ err = fdt_open_into (fdt_blob, of_start, of_len);
+ if (err != 0) {
+ fdt_error ("fdt move failed");
+ goto error;
+ }
+ puts ("OK\n");
}
- puts ("OK\n");
*of_flat_tree = of_start;
*of_size = of_len;