As the trade war between the US and China continues to unfold, we are seeing major US companies ban or stop providing service to China's technology giant Huawei. Now, it looks like the trade war has crossed the ocean and reached the UK. This time, UK based ARM Holdings, the provider of mobile chip IP for nearly all smartphones and tablets, has revoked the license it has given Huawei.

According to the BBC, ARM Holdings employees were instructed to suspend all interactions with Huawei, and to send a note informing Huawei that "due to an unfortunate situation, they were not allowed to provide support, deliver technology (whether software, code, or other updates), engage in technical discussions, or otherwise discuss technical matters with Huawei, HiSilicon or any of the other named entities." The news came from an internal ARM document the BBC has obtained.So, what does this mean?

For starters, let's elaborate a bit on what exactly ARM's business is, and what connections they have with Huawei. ARM is the license provider of the ARM processor IP, which is used in all CPUs that are built around the ARM instruction set architecture. That means that whenever a microchip is designed using the ARM ISA, in order to be commercially sold, ARM needs to approve it. Those approvals are of course followed by a fixed fee the licensee is paying. How does that affect Huawei you might ask. A lot, actually. ARM is found in every chip Huawei designs and sells. Huawei's subsidiary, HiSilicon actually designs the chips, but that makes no difference. There exists a company called "ARM-China" but it has terminated the contract with Huawei as well.

The big questions now is, whether this termination affects existing devices sitting on retailer shelves, existing processors sitting in warehouses, chips currently being fabricated, or only future chip designs. In the worst case it could mean that Huawei is facing an immediate sales ban of all their phones or tablets using ARM processors, which will be a huge deal for the company.

What I think will happen in the short-term, is that they will most likely try to outsource chip manufacturing to someone with a license, like MediaTek (China) or Samsung (Korea), or adopt another industry standard ISA. A good candidate for that would be RISC-V, which is a (relatively) new and open architecture that requires no licensing. Having seen huge growth in China for all kinds of applications, from AI to IoT, RISC-V would be a logical decision, especially since the architecture is royalty-free.

But there is a problem. Currently, all of Huawei's efforts have been focused on Android, which is basically tailor-made for ARM chips. Android, mind you, is running on top of Linux, which has been ported to various other architectures in the past. The Linux kernel itself already supports RISC-V, and is available in distributions like Debian, Fedora, FreeBSD and NetBSD, so there exists a possibility that Huawei will build its new software and hardware stack on top of those.