Google firmware users may think that they have every reason to celebrate with the anticipated release of Android Marshmallow on Sept. 29, however, they have to know that this good news will only benefit some.

According to Marie Brewis of PC Advisor, the so-called Android M can only be enjoyed by those who have a Nexus 5, Nexus 6, Nexus 9 or Nexus Player.

Therefore, if you are using a mobile unit other than the ones mentioned, the Google event at the end of this month might just end your excitement. The release of the latest update will coincide with the unveiling of Nexus 5 and Nexus 6.

Nevertheless, the tech site writer noted that high-end devices produced by some established makers may eventually upgrade them to Android Marshmallow, but definitely not during its release this month.

"If it's a high-end device from a well-known manufacturer such as Sony, Samsung or HTC, it's almost certain that an upgrade to Marshmallow will become available to it," Brewis pointed out.

"However, don't expect to get the upgrade until early 2016, since it will first roll out to Nexus devices," she added.

Brewis further shared that "cheaper and older smartphones, or those from smaller manufacturers" may face the risk of not enjoying the upgrade anymore because of "fragmentation" issue.

Meanwhile, Android.gs reported that several Samsung smartphone models will also receive the Android Marshmallow update, yet its release or availability for download is still unknown.

 The site claimed that "Without a doubt, the South Koreans will make the Android 6.0 Marshmallow update for Samsung Galaxy S6, Galaxy Note 5, Galaxy S5, and Galaxy Note 4 available for download, but we are wondering when will this moment arrive."

It was likewise revealed that the firmware's update for the cited Samsung models will be pushed "gradually" both over-the-air or through KIES.

In the meantime, to know if there is a pending update to install, the site suggested that owners of these smartphones must check their notifications bar.

Another important detail cited in the article was about the release of the Android Marshmallow update for other variants of the Samsung smartphones like the Galaxy S6 Edge or a Galaxy S6 Edge Plus.