On Thu, Dec 28, 2023 at 01:36:54PM +0000, Simon Glass wrote:
Standard passage provides for a bloblist to be passed from one firmware phase to the next. That can be used to pass the devicetree along as well. Add an option to support this.
Tests for this will be added as part of the Universal Payload work.
Signed-off-by: Simon Glass sjg@chromium.org
The discussion on this was not resolved and is now important due to the bloblist series from Raymond. So I am sending it again since I believe this is a better starting point than building on OF_BOARD
[snip]
@@ -1662,23 +1667,42 @@ static void setup_multi_dtb_fit(void)
int fdtdec_setup(void) {
- int ret;
- int ret = -ENOENT;
- /* If allowing a bloblist, check that first */
- if (CONFIG_IS_ENABLED(OF_BLOBLIST)) {
ret = bloblist_maybe_init();if (!ret) {gd->fdt_blob = bloblist_find(BLOBLISTT_CONTROL_FDT, 0);if (gd->fdt_blob) {gd->fdt_src = FDTSRC_BLOBLIST;log_debug("Devicetree is in bloblist at %p\n",gd->fdt_blob);} else {log_debug("No FDT found in bloblist\n");ret = -ENOENT;}}- }
- /* The devicetree is typically appended to U-Boot */
- if (IS_ENABLED(CONFIG_OF_SEPARATE)) {
gd->fdt_blob = fdt_find_separate();gd->fdt_src = FDTSRC_SEPARATE;- } else { /* embed dtb in ELF file for testing / development */
gd->fdt_blob = dtb_dt_embedded();gd->fdt_src = FDTSRC_EMBED;
- /* Otherwise, the devicetree is typically appended to U-Boot */
- if (ret) {
if (IS_ENABLED(CONFIG_OF_SEPARATE)) {gd->fdt_blob = fdt_find_separate();gd->fdt_src = FDTSRC_SEPARATE;} else { /* embed dtb in ELF file for testing / development */gd->fdt_blob = dtb_dt_embedded();gd->fdt_src = FDTSRC_EMBED;}
This whole if/else tree looks wrong today, and then wrong with this patch. If we have an embedded device tree, which should only be used for development (or special case needs, I _think_ some users today are using this for security type needs), it must win and be used. The over-ride switch was set, and should be used. Then, I don't know if we should be saying "the user provided a tree via OF_SEPARATE, it should be used" or "the device has passed us a tree via standard mechanism, it should be used" is the higher priority. I really don't know which is more valid.