The firmware is cross-compiled, but the build system ends up using
'objcopy' instead of 'xtensa-elf-objcopy' by default.  Force it to
use the right one.

--- source/target_firmware/configure	2014-10-28 20:57:26.834436561 +0100
+++ source/target_firmware/configure	2014-10-28 20:57:29.666436530 +0100
@@ -11,6 +11,7 @@ mkdir -p build
 cat > "$TOOLCHAIN_FILE" <<EOF
 INCLUDE(CMakeForceCompiler)
 
+SET(CMAKE_OBJCOPY xtensa-elf-objcopy)
 SET(CMAKE_SYSTEM_PROCESSOR xtensa)
 SET(CMAKE_FIND_ROOT_PATH ${TOOLCHAIN}/$TARGET)
 SET(CMAKE_STRIP :)
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<tr><td><span title='2020-10-01 15:47:29 +0200'>2020-10-01</span></td><td><a href='/guix/commit/gnu/tests/virtualization.scm?id=18e76f89055f25f015fadb7c999b410f38a88cc6'>services: hurd-vm: Resurrect system-test by using raw disk-image.</a><span class='msg-avail'>...</span></td><td>Jan (janneke) Nieuwenhuizen</td></tr>
<tr><td><span title='2020-09-29 21:56:28 +0200'>2020-09-29</span></td><td><a href='/guix/commit/gnu/tests/virtualization.scm?id=c11c19bd4d0dc4ec56b949647057dbf00567f2ae'>services: hurd-vm: Add system test.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>