rootfsinstall.sh: rpi: boot partition increased from 40 to 100MB; config.txt update for rpi4 compatibility

src/rootfsinstall.sh

@@ -201,7 +201,7 @@ case $TARGETDEVICE in
         ;;
    rpi) ARCH=arm
         BOOTFSTYPE=fat32
-        BOOTFSSIZE=40M
+        BOOTFSSIZE=100M
         BOOTFSSTART=0
         [ "$USEKERNEL" ] || USEKERNEL="zImage-*-rpi"
         [ "$USEKERNEL2" ] || USEKERNEL2="zImage-*-rpi-v7"
@@ -561,10 +561,6 @@ splash" > $BOOTMP/cmdline.txt
    # Create the kernel configuration file
    [ ! -e $ROOTMP/boot/config.txt ] && \
    echo "\
-start_file=start_x.elf
-fixup_file=fixup_x.dat
-framebuffer_depth=32
-framebuffer_ignore_alpha=1
 [rp1]
 arm_freq=800
 force_turbo=1
@@ -572,6 +568,11 @@ gpu_mem=100
 disable_overscan=1
 [rp2]
 gpu_mem=128
+[all]
+start_x=1
+framebuffer_depth=32
+framebuffer_ignore_alpha=1
+dtparam=audio=on
 " > $BOOTMP/config.txt
 
    ## Enable HDMI mode rather than DVI, if required