diff --git a/tools/osbuilder/README.md b/tools/osbuilder/README.md
index 783a535a4..b6f9bd161 100644
--- a/tools/osbuilder/README.md
+++ b/tools/osbuilder/README.md
@@ -65,6 +65,13 @@ This section describes the terms used for all documentation in this repository.
   A guest OS build method where the building host is used as the Base OS.
   For more information refer to the [dracut homepage](https://dracut.wiki.kernel.org/index.php/Main_Page).
 
+- Agent init
+
+  The Guest OS should have the Kata Containers agent started on boot time.
+
+  That is achieved by using a system manager (for example, systemd) which
+  will evoke the agent binary; or having the agent itself as the init process.
+
 ## Building
 
 The top-level `Makefile` contains an example of how to use the available components.
diff --git a/tools/osbuilder/image-builder/Dockerfile b/tools/osbuilder/image-builder/Dockerfile
index c32792258..535136aa0 100644
--- a/tools/osbuilder/image-builder/Dockerfile
+++ b/tools/osbuilder/image-builder/Dockerfile
@@ -3,7 +3,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-From docker.io/fedora:latest
+From registry.fedoraproject.org/fedora:latest
 
 RUN [ -n "$http_proxy" ] && sed -i '$ a proxy='$http_proxy /etc/dnf/dnf.conf ; true
 
diff --git a/tools/osbuilder/image-builder/image_builder.sh b/tools/osbuilder/image-builder/image_builder.sh
index 1cc18552c..6f18946b4 100755
--- a/tools/osbuilder/image-builder/image_builder.sh
+++ b/tools/osbuilder/image-builder/image_builder.sh
@@ -113,7 +113,7 @@ Rootfs: partition that contains the root filesystem (/usr, /bin, ect).
 
 Kernels and hypervisors that support DAX/NVDIMM read the MBR #2, otherwise MBR #1 is read.
 
-[1] - https://github.com/kata-containers/osbuilder/blob/master/image-builder/nsdax.gpl.c
+[1] - https://github.com/kata-containers/kata-containers/blob/main/tools/osbuilder/image-builder/nsdax.gpl.c
 [2] - https://github.com/torvalds/linux/blob/master/drivers/nvdimm/pfn.h
 
 EOT
diff --git a/tools/osbuilder/rootfs-builder/README.md b/tools/osbuilder/rootfs-builder/README.md
index 9ceb1b7a2..c49b58f86 100644
--- a/tools/osbuilder/rootfs-builder/README.md
+++ b/tools/osbuilder/rootfs-builder/README.md
@@ -50,7 +50,7 @@ $ ./rootfs.sh -r "$PWD/kata-overlay"
 
 The rootfs must provide at least the following components:
 
-- [Kata agent](https://github.com/kata-containers/agent)
+- [Kata agent](https://github.com/kata-containers/kata-containers/tree/main/src/agent)
 
   Path: `/bin/kata-agent` - Kata Containers guest.
 
diff --git a/tools/osbuilder/rootfs-builder/centos/Dockerfile.in b/tools/osbuilder/rootfs-builder/centos/Dockerfile.in
index c7714ad18..2e29195ea 100644
--- a/tools/osbuilder/rootfs-builder/centos/Dockerfile.in
+++ b/tools/osbuilder/rootfs-builder/centos/Dockerfile.in
@@ -3,7 +3,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-From docker.io/centos:@OS_VERSION@
+From registry.centos.org/centos:@OS_VERSION@
 
 @SET_PROXY@
 
diff --git a/tools/osbuilder/rootfs-builder/fedora/Dockerfile.in b/tools/osbuilder/rootfs-builder/fedora/Dockerfile.in
index b67203341..5d66c5c47 100644
--- a/tools/osbuilder/rootfs-builder/fedora/Dockerfile.in
+++ b/tools/osbuilder/rootfs-builder/fedora/Dockerfile.in
@@ -3,7 +3,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-From docker.io/fedora:@OS_VERSION@
+From registry.fedoraproject.org/fedora:@OS_VERSION@
 
 @SET_PROXY@
 
diff --git a/tools/osbuilder/rootfs-builder/rootfs.sh b/tools/osbuilder/rootfs-builder/rootfs.sh
index 4d69e89d9..b2330040b 100755
--- a/tools/osbuilder/rootfs-builder/rootfs.sh
+++ b/tools/osbuilder/rootfs-builder/rootfs.sh
@@ -147,7 +147,7 @@ DOCKER_RUNTIME      Docker runtime to use when USE_DOCKER is set.
 
 Refer to the Platform-OS Compatibility Matrix for more details on the supported
 architectures:
-https://github.com/kata-containers/osbuilder#platform-distro-compatibility-matrix
+https://github.com/kata-containers/kata-containers/tree/main/tools/osbuilder#platform-distro-compatibility-matrix
 
 EOT
 exit "${error}"