QcomModulePkg: Re-enable multiple appended DTB supportrelease/LU.UM.1.2.1.r1-23200-QRB5165.0

Now that qcom,msm-id and qcom,board-id for db845c and rb5
are merged upstream (v5.16), re-enable the multiple
appended DTB suport.

This patch is compatible with older kernel builds. It will
fallback to the option of choosing the first appended DTB
in case the qcom* IDs are missing or there is no match.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>

1 files changed, 18 insertions, 11 deletions

diff --git a/QcomModulePkg/Library/BootLib/LocateDeviceTree.c b/QcomModulePkg/Library/BootLib/LocateDeviceTree.c
index cab043bfd..842f61c17 100644
--- a/QcomModulePkg/Library/BootLib/LocateDeviceTree.c
+++ b/QcomModulePkg/Library/BootLib/LocateDeviceTree.c
@@ -922,6 +922,7 @@ GetSocDtb (VOID *Kernel, UINT32 KernelSize, UINT32 DtbOffset, VOID *DtbLoadAddr)
 {
   uintptr_t KernelEnd = (uintptr_t)Kernel + KernelSize;
   VOID *Dtb = NULL;
+  VOID *FallbackDtb = NULL;
   struct fdt_header DtbHdr;
   UINT32 DtbSize = 0;
   INT32 DtbCount = 0;
@@ -935,7 +936,7 @@ GetSocDtb (VOID *Kernel, UINT32 KernelSize, UINT32 DtbOffset, VOID *DtbLoadAddr)
   if (((uintptr_t)Kernel + (uintptr_t)DtbOffset) < (uintptr_t)Kernel) {
     return NULL;
   }
-  Dtb = Kernel + DtbOffset;
+  FallbackDtb = Dtb = Kernel + DtbOffset;
   while (((uintptr_t)Dtb + sizeof (struct fdt_header)) < (uintptr_t)KernelEnd) {
     /* the DTB could be unaligned, so extract the header,
      * and operate on it separately */
@@ -948,14 +949,6 @@ GetSocDtb (VOID *Kernel, UINT32 KernelSize, UINT32 DtbOffset, VOID *DtbLoadAddr)
       break;
 
     CurDtbInfo.Dtb = Dtb;
-    /*
-     * HACK: set Current (and only dtb in our case) as the Best match explicitly.
-     * Default behaviour is to iterate thru the list of dtbs in dtb.img and pick
-     * the best match based on DTMATCH_PARAMS (qcom,{msm-id/board-id/pmic-id} in
-     * dts). msm-id/board-id/pmic-id are non-upstream dt properties which we do
-     * not support on db845c.
-     */
-    BestDtbInfo.Dtb = Dtb;
     if (ReadDtbFindMatch (&CurDtbInfo, &BestDtbInfo, SOC_MATCH)) {
         DtbIdx = DtbCount;
     }
@@ -982,8 +975,22 @@ GetSocDtb (VOID *Kernel, UINT32 KernelSize, UINT32 DtbOffset, VOID *DtbLoadAddr)
   }
 
   if (!BestDtbInfo.Dtb) {
-    DEBUG ((EFI_D_ERROR, "No match found for Soc Dtb type\n"));
-    return NULL;
+    if (!FallbackDtb) {
+      DEBUG ((EFI_D_ERROR, "No match found for Soc Dtb type\n"));
+      return NULL;
+    } else {
+      DEBUG ((EFI_D_INFO, "No match found for Soc Dtb type, fallback to the default Dtb\n"));
+      /*
+       * For Linux kernel builds (v5.15 and below), set the default dtb in
+       * boot.img/vendor_boot.img as the Best match explicitly.
+       * Default behaviour is to iterate thru the list of dtbs in dtb.img
+       * and pick the best match based on DTMATCH_PARAMS properties
+       * (qcom,{msm-id/board-id/pmic-id} in dts. But the msm-id and board-id
+       * of RB5 and db845c got upstreamed in v5.16 only, so this hack
+       * provides a dtb fallback to the older kernel builds.
+       */
+      BestDtbInfo.Dtb = FallbackDtb;
+    }
   }
 
   return BestDtbInfo.Dtb;