Make LoadKernel() pass back the kernel partition's UniqueGuid.

firmware/include/load_kernel_fw.h

Index: firmware/include/load_kernel_fw.h
diff --git a/firmware/include/load_kernel_fw.h b/firmware/include/load_kernel_fw.h
index 31c30818359b4cd8d0ea824a7b5e503c11fa008a..4cca8bd57b58f6a1f6a9edb8ca3e0c2bf8b98cd3 100644
--- a/firmware/include/load_kernel_fw.h
+++ b/firmware/include/load_kernel_fw.h
@@ -44,6 +44,7 @@ typedef struct LoadKernelParams {
                                  * (1...M) */
   uint64_t bootloader_address;  /* Address of bootloader image in RAM */
   uint64_t bootloader_size;     /* Size of bootloader image in bytes */
+  uint8_t  partition_guid[16];  /* UniquePartitionGuid for boot partition */
 } LoadKernelParams;
 
 int LoadKernel(LoadKernelParams* params);
@@ -62,6 +63,7 @@ typedef struct KernelBootloaderOptions {
   uint64_t original_address;    /* Absolute bootloader start adddress,
                                  * as returned from LoadKernel() in
                                  * LoadKernelParams.bootloader_start */
+  uint8_t  partition_guid[16];  /* UniquePartitionGuid for boot partition */
 } KernelBootloaderOptions;