pico-sdk: Import picotool as a dependency

We were previously not handling picotool at all, and
pico-sdk would download picotool itself, at build time.

This means that the source archive, if created, would
not contain picotool. While not strictly required, for
complete corresponding source, since it's a toolchain
and not the actual pico-serprog firmware, it is my policy
that releases must include full corresponding source code,
when it is feasible to do so.

I must say, I intensely dislike cmake, with such burning
passion; I am thoroughly displeased by how hacky this is,
but it works and now nothing is in my way for a Libreboot
20241206 rev8 release!

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/rom.sh

@@ -7,6 +7,9 @@
 
 mkserprog()
 {
+	[ $# -lt 1 ] && $err "mkserprog: no arguments provided"
+	[ "$1" = "pico" ] && mkpicotool
+
 	[ "$_f" = "-d" ] && return 0 # dry run
 	basename -as .h "$serdir/"*.h > "$TMPDIR/ser" || $err "!mk $1 $TMPDIR"
 
@@ -20,6 +23,7 @@ mkserprog()
 			ln -srf "$sersrc/build_$pt/" "$sersrc/build") \
 		    && x_ cmake -DPICO_BOARD="$sertarget" \
 		    -DPICO_SDK_PATH="$picosdk" -B "$sersrc/build" "$sersrc" \
+		    -Dpicotool_DIR="$picotool/picotool" \
 		    && x_ cmake --build "$sersrc/build"
 		[ "$1" = "stm32" ] && x_ make -C "$sersrc" \
 		    libopencm3-just-make BOARD=$sertarget && x_ make -C \
@@ -30,6 +34,18 @@ mkserprog()
 	[ "$XBMK_RELEASE" = "y" ] && mkrom_tarball "bin/serprog_$1"; return 0
 }
 
+mkpicotool()
+{
+	rm -Rf "$picotool" || $err "Can't remove picotool builddir"
+	(
+	x_ cd src/picotool
+	cmake -DCMAKE_INSTALL_PREFIX=xbmkbin -DPICOTOOL_FLAT_INSTALL=1 \
+	    -DPICO_SDK_PATH=../pico-sdk || \
+	    $err "Can't prep picotool"
+	make install || $err "Can't build picotool"; :
+	) || $err "Can't build picotool"; :
+}
+
 copyps1bios()
 {
 	x_ rm -Rf bin/playstation