在yocto中添加层时出现问题

我对yocto很陌生,正在努力学习如何使用它。我遵循了mega手册一节中的步骤 section 5.1.9 . 我跑了

yocto-layer create mylayer

编辑我的bblayers。conf文件包含以下内容:

 BBLAYERS = ?" \
    /usr/local/src/yocto/meta \
    /usr/local/src/yocto/meta-poky \
    /usr/local/src/yocto/meta-yocto-bsp \
    /usr/local/src/yocto/meta-mylayer \
    "

我跑了 source oe-init-build-env 然后 bitbake core-image-sato runqemu qemu86 nographics 登录后 find / -name helloworld

# We have a conf and classes directory, add to BBPATH
BBPATH .= ":${LAYERDIR}"

# We have recipes-* directories, add to BBFILES
BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
    ${LAYERDIR}/recipes-*/*/*.bbappend"

BBFILE_COLLECTIONS += "mylayer"
BBFILE_PATTERN_mylayer = "^${LAYERDIR}/"
BBFILE_PRIORITY_mylayer = "6"

#
# This file was derived from the 'Hello World!' example recipe in the
# Yocto Project Development Manual.
#

SUMMARY = "Simple helloworld application"
SECTION = "examples"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

SRC_URI = "file://helloworld.c"

S = "${WORKDIR}"

do_compile() {
     ${CC} ${LDFLAGS} helloworld.c -o helloworld
}

do_install() {
     install -d ${D}${bindir}
     install -m 0755 helloworld ${D}${bindir}
}

meta-mylayer/recipes-example/example/example-0.1/helloworld。c:

#include <stdio.h>

int main(int argc, char **argv)
{
    printf("Hello World!\n");

    return 0;
}