ArmVirtPkg/XenRelocatablePlatformLib: rewrite DTB memory node retrieval in C

[mirror_edk2.git] / ArmVirtPkg / Library / ArmXenRelocatablePlatformLib / AARCH64 / RelocatableVirtHelper.S

diff --git a/ArmVirtPkg/Library/ArmXenRelocatablePlatformLib/AARCH64/RelocatableVirtHelper.S b/ArmVirtPkg/Library/ArmXenRelocatablePlatformLib/AARCH64/RelocatableVirtHelper.S
index d6edc62efc0dcb08153d9c076cfbde8bccb92def..ae77492bf363253514703632abaf6a2cb7d7a286 100644 (file)
--- a/ArmVirtPkg/Library/ArmXenRelocatablePlatformLib/AARCH64/RelocatableVirtHelper.S
+++ b/ArmVirtPkg/Library/ArmXenRelocatablePlatformLib/AARCH64/RelocatableVirtHelper.S
@@ -30,9 +30,6 @@ GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdArmPrimaryCore)
 GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdArmPrimaryCoreMask)\r
 GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdCoreCount)\r
 \r
-.LFdtMagic:\r
-  .byte   0xd0, 0x0d, 0xfe, 0xed\r
-\r
 .LArm64LinuxMagic:\r
   .byte   0x41, 0x52, 0x4d, 0x64\r
 \r
@@ -43,17 +40,15 @@ GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdCoreCount)
 //   );\r
 ASM_PFX(ArmPlatformPeiBootAction):\r
   mov   x29, x30            // preserve LR\r
+  mov   x28, x0             // preserve DTB pointer\r
+  mov   x27, x1             // preserve base of image pointer\r
 \r
   //\r
   // If we are booting from RAM using the Linux kernel boot protocol, x0 will\r
   // point to the DTB image in memory. Otherwise, we are just coming out of\r
-  // reset, and x0 will be 0. Check also the FDT magic.\r
+  // reset, and x0 will be 0.\r
   //\r
   cbz   x0, .Lout\r
-  ldr   w8, .LFdtMagic\r
-  ldr   w9, [x0]\r
-  cmp   w8, w9\r
-  bne   .Lout\r
 \r
   //\r
   // The base of the runtime image has been preserved in x1. Check whether\r
@@ -80,36 +75,30 @@ ASM_PFX(ArmPlatformPeiBootAction):
   str   x1, [x8]\r
   str   x7, [x9]\r
 \r
+  //\r
+  // Discover the memory size and offset from the DTB, and record in the\r
+  // respective PCDs. This will also return false if a corrupt DTB is\r
+  // encountered. Since we are calling a C function, use the window at the\r
+  // beginning of the FD image as a temp stack.\r
+  //\r
+  adr   x1, PcdGet64 (PcdSystemMemorySize)\r
+  adr   x2, PcdGet64 (PcdSystemMemoryBase)\r
+  mov   sp, x7\r
+  bl    FindMemnode\r
+  cbz   x0, .Lout\r
+\r
   //\r
   // Copy the DTB to the slack space right after the 64 byte arm64/Linux style\r
   // image header at the base of this image (defined in the FDF), and record the\r
   // pointer in PcdDeviceTreeInitialBaseAddress.\r
   //\r
   adr   x8, PcdGet64 (PcdDeviceTreeInitialBaseAddress)\r
-  add   x1, x1, #0x40\r
-  str   x1, [x8]\r
-\r
-  ldr   w8, [x0, #4]          // get DTB size (BE)\r
-  mov   x9, x1\r
-  rev   w8, w8\r
-  add   x8, x8, x0\r
-0:ldp   x6, x7, [x0], #16\r
-  stp   x6, x7, [x9], #16\r
-  cmp   x0, x8\r
-  blt   0b\r
-\r
-  //\r
-  // Discover the memory size and offset from the DTB, and record in the\r
-  // respective PCDs\r
-  //\r
-  mov   x0, x1\r
-  bl    find_memnode    // returns (size, base) size in (x0, x1)\r
-  cbz   x0, .Lout\r
+  add   x27, x27, #0x40\r
+  str   x27, [x8]\r
 \r
-  adr   x8, PcdGet64 (PcdSystemMemorySize)\r
-  adr   x9, PcdGet64 (PcdSystemMemoryBase)\r
-  str   x0, [x8]\r
-  str   x1, [x9]\r
+  mov   x0, x27\r
+  mov   x1, x28\r
+  bl    CopyFdt\r
 \r
 .Lout:\r
   ret    x29\r