PhoenixBIOS is a personal computer BIOS first released by Phoenix Technologies (at the time named Phoenix Software Associates) in 1984. It is the first IBM PC compatible BIOS that could be legally licensed to other system vendors, thus marking the beginning of the competition between Phoenix and other commercial BIOS vendors that later released their own solutions, such as American Megatrends with AMIBIOS and Award Software with AwardBIOS.
Since the late 2000s and early 2010s, it has been mostly replaced by SecureCore, a UEFI firmware released by the same company.
Reverse engineering of the IBM PC BIOS
Prior to PhoenixBIOS' introduction, OEMs usually copied portions of the IBM PC's BIOS source code from reference manuals, to develop their own BIOS to be used on compatible clones of the system. This caused copyright infringement and was therefore illegal, commonly resulting in legal action being taken by IBM against the offending OEM.[1] A few OEMs managed to develop their own solution without infringing IBM's copyright. However, these were either not available for licensing to other OEMs (e.g. Compaq BIOS) or were only partially compatible with IBM PC software.
PhoenixBIOS was developed using a reverse engineering method named Chinese wall to avoid copyright infringement. Using this method, one group of engineers first read the reference manuals to reverse engineer various functions of the BIOS, documenting how they worked without writing any actual code. Then, they passed those documents to another engineer who wrote his own code to mimic those functions. According to Phoenix's Vice President of Marketing, Lance Hansche, "He (the engineer) was a TI-9900 programmer" and that "The TI-9900 processor is stack oriented, it doesn't have registers like the 8088" and also that "There's no way his code could be the same as IBM's, it took us 3 months of memos to convince him to use registers at all!"[2]. During this process, the audit trail of both groups' interactions was also recorded to prove the legality of the process.
Theoretically, since the engineer that wrote the BIOS never looked at any reference manuals, he could not have copied the IBM BIOS source code. Therefore, this solution did not infringe IBM's copyright and was legal.
List of known versions
The following is a list of known versions of PhoenixBIOS.
| Main version | Release date | Variants | POST screen | Notes |
|---|---|---|---|---|
| Phoenix ROM BIOS Ver 1.xx | 1984 | |||
| Phoenix ROM BIOS Ver 2.xx | 1986(?) | |||
| Phoenix ROM BIOS PLUS | 1987 | A code fork by Dell exists, which was in use until around 2015. Likely internally considered as PhoenixBIOS 3.xx by Phoenix. | ||
| PhoenixBIOS 4.0x | 1988 |
|
A code fork by Intel exists, usually used on their very early motherboards. | |
| PhoenixBIOS Ax86 | 1990(?) | |||
| PhoenixBIOS 4.0 Release 6.x | 1997 |
|
Also used by VMware for the legacy BIOS option. Code forks by Intel and Siemens-Nixdorf/Fujitsu-Siemens also exists, with the latter usually being called "PhoenixBIOS 4.06". This fork may also be based on a pre-release version. | |
| Phoenix cME FirstBIOS | 2004 |
- ↑ https://books.google.com/books?id=gy4EAAAAMBAJ&pg=PA15
- ↑ https://books.google.com/books?id=Bwng8NJ5fesC&pg=PA56
- ↑ https://web.archive.org/web/19980701101921/http://www.phoenix.com/desktop/server.pdf
- ↑ https://www.thefreelibrary.com/Phoenix+Technologies+launches+ServerBIOS+3.5+grid+edition+and...-a094959841