<div dir="ltr">Hi Alexander,<br><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Jun 28, 2017 at 1:46 PM, Alexander Kapshuk <span dir="ltr"><<a href="mailto:alexander.kapshuk@gmail.com" target="_blank">alexander.kapshuk@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">I am trying to setup a build environment where I can run the kernel and see how the changes I have made to the kernel source work.<div>My understanding, based on googling, is that it is common practice in the kernel community to use a virtualised environment for that purpose.</div><div>What I have done so far is create a ramfs that is built into the kernel, as described here [1] and here [2].</div><div><br></div><div>[1] <a href="https://landley.net/writing/rootfs-howto.html" target="_blank">https://landley.net/<wbr>writing/rootfs-howto.html</a></div><div>[2] <a href="https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/Documentation/early-userspace/README?h=v4.12-rc7" target="_blank">https://git.kernel.org/<wbr>pub/scm/linux/kernel/git/<wbr>torvalds/linux.git/plain/<wbr>Documentation/early-userspace/<wbr>README?h=v4.12-rc7</a></div><div><br></div><div>a). I have generated a minimal initramfs_list file:</div><div>scripts/gen_initramfs_list.sh -d >usr/initramfs_list<br></div><div>Which looks like this:</div><div><div># This is a very simple, default initramfs</div><div><br></div><div>dir /dev 0755 0 0</div><div>nod /dev/console 0600 0 0 c 5 1</div><div>dir /root 0700 0 0</div><div># file /kinit usr/kinit/kinit 0755 0 0</div><div># slink /init kinit 0755 0 0</div><div>slink /bin/sh busybox 777 0 0</div><div>file /init /bin/busybox 755 0 0</div></div><div><br></div><div>b). Set CONFIG_INITRAMFS_SOURCE:</div><div>CONFIG_INITRAMFS_SOURCE="/<wbr>home/sasha/linux/usr/<wbr>initramfs_list"<br></div><div><br></div><div>c). And had the kernel generate the initramfs image:</div><div><div>make</div><div>...</div><div>GEN usr/initramfs_data.cpio.gz</div><div> CHK include/generated/compile.h</div><div> AS usr/initramfs_data.o</div><div> LD usr/built-in.o</div><div>...</div></div><div><br></div><div>When I run the kernel in qemu I get an error message which complains about /etc/init.d/rcS missing.</div></div></blockquote><div><br></div><div>Did you check initramfs for rc.S script?</div><div><br></div><div>The kernel configuration, busybox configuration and the layout of initramfs (which should be /<wbr>home/sasha/linux/usr/<wbr>initramfs_list) should be consistent. If the kernel is asking for it then it is not consistent.</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>The posts online seem to suggest that this has got to do with the busybox configuration.</div><div>So far, I have not been able to get my head around this problem.</div><div>Any points or suggestions would be much appreciated.</div><span class="gmail-HOEnZb"><font color="#888888"><div><br></div><div>Alexander Kapshuk.</div><div><br></div></font></span></div>
<br>______________________________<wbr>_________________<br>
Kernelnewbies mailing list<br>
<a href="mailto:Kernelnewbies@kernelnewbies.org">Kernelnewbies@kernelnewbies.<wbr>org</a><br>
<a href="https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies" rel="noreferrer" target="_blank">https://lists.kernelnewbies.<wbr>org/mailman/listinfo/<wbr>kernelnewbies</a><br>
<br></blockquote></div><br><br clear="all"><div>Thank you.</div><div class="gmail_signature">Shahbaz Khan<br></div>
</div></div>