Firmware is essentially software that is embedded on a hardware device and directly controls it (resets, initializes and configures) before the operating system (for example, the Solaris Operating System, Linux, or Microsoft Windows) is booted. The firmware is what actually boots the OS, and it is usually contained in some sort of Flash PROM on a system board.

Unlike an OS, which is designed to run on lots of different configurations of hardware and occupies a lot of room (10s or 100s of megabytes) on the disk, firmware is usually space-constrained to a few megabytes (sometimes less than that), so it usually contains only the code needed for that specific hardware configuration. That is why each Sun system gets its own separate release of firmware. Firmware specific to one type of system will usually not function on a different system.

All Sun systems ship with firmware already installed on them from the factory. However, like any piece of software, Sun is constantly improving its firmware over time, even after a system has started shipping. So, yes, there are situations when updating the firmware on your system is recommended. Some of these reasons include:

• Support for new versions of hardware (or peripherals)
• Expanded compatibility and enhancements
• Better reliability and system availability
• Better system performance
• Additional system features
• Security fixes
• Other bug fixes

Often, Sun servers might be power-cycled or rebooted only a few times per year, so you might think new firmware is not needed if the current system works fine and the configuration has not changed. If so, then there may be no reason to update your firmware.

Today's Sun System Firmware on the Sun CMT line of products using CoolThreads technology, includes the virtualization engine (Hypervisor). After the Solaris OS has booted, the Sun System Firmware is still operating, unlike in the past with OBP, which did little after the OS was booted.

The Sun Logical Domains (LDoms) virtualization feature depends on the Hypervisor running in the System Firmware and the LDoms Manager software to operate, in addition to requiring the latest improvements at the Solaris OS level. The virtualization feature sets in Solaris and LDoms are closely tied to the corresponding releases of the Hypervisor in System Firmware. Along with new features you also get bug fixes and performance improvements. If you need to update or patch your Solaris OS, then you should also be upgrading your System Firmware.

Every Sun System Firmware release includes a patch README file that describes what changes have been made in this firmware release. The README will contain a standard header area, and also the following sections of note:

• BugId's fixed with this patch:
  This section includes a full list of all bugs associated with the base patch-ID, starting from the -01 version. The bugs are usually sorted in numerical order to make them easier to scan through.
• Changes incorporated in this version:
  Bugs listed here are a subset of the "BugID's fixed with this patch" and include only the bugs delivered in the latest dash-roll of the base patch-ID.
• Problem Description:
  This section also lists the same bugs from the "BugID's fixed with this patch" section, except they are broken out by the dash-roll increments and also they are listed one bug per line with the Synopsis included.
• Special Install Instructions:
  This section will include a series of Notes, some of which are standard for Sun System Firmware, such as:
  • Firmware component revisions included with this release - lists the release version and all component versions.
  • Advice on compatibility with the LDoms feature.
  • Pointer to any Open Source components.

It is recommended that you always review these Notes before installing the Sun System Firmware on your server.

There are two answers to this question. First, the number of bug fixes is higher for Sun System Firmware than some older server systems because the firmware itself has far more functionality than prior systems, as noted above. The more functionality, the higher the bug fix count is going to be, on average, from release to release.

Second, Sun System Firmware uses a common source base for all of the Sun CMT server systems. The Bugs Fixed list in the README for a given system will include bug fixes that are specific to that system, as well as bug fixes that are known to be relevant to more than one (or all) systems, and as the number of supported systems grows, the number of shared bugs grows as well. It is impractical to fully describe the relevance of each bug fix to a given system, so we list all bugs that are either known to be relevant or otherwise in known common code, under the theory that more disclosure is better than less. That said, we do exclude bug fixes known to be specific to a given system from the README list of all other types of systems.

Sun firmware is available for download from two different channels, depending on which Sun system is involved. Sun uses both the SunSolve site and the Sun Download Center.

This is because the two locations evolved at different times and focused on different parts of the product line. Sun has been selling a broad spectrum of workstations and servers for many years, and SunSolve, which is primarily a channel for obtaining Solaris patches and application-level patches, was the original site used by the low-end workstations and entry-level servers to distribute firmware updates. In fact, the term "patches" is used on the SunSolve site because the term is baked into the SunSolve site itself, even though Sun firmware is always released as a complete, fully functional image, and it is not in any way technically related to how the Solaris OS applies patches to itself. Firmware patches are non-standard patches in that they are not installed with patchadd, but are flashed onto the hardware manually.

The Sun Download Center evolved later and tended to service the higher-end enterprise servers (for example, the Sun Fire E10K and E25K), as well as some firmware products that applied to an entire family of systems (for example, RSC and ALOM for low-end service processors).

The x64 based Sun servers generally release a Tools & Drivers CD image that will contain firmware objects, such as the BIOS and ILOM service processor. Additionally, there are utilities and drivers provided for Windows and Linux that are needed by the specific server system. These Tools & Drivers CD ISO images for x64 servers are downloadable from the Sun Download Center.

Philosophically, it would make more sense to use the Sun Download Center, which is more about downloading software products than Solaris patches. However, the Sun Download Center is organized around independent software products, which also tend to not be organized around hardware systems. Yes, Sun firmware is a single conceptual product category, but it is released independently for each hardware system. Sun chose to use SunSolve not because SunSolve is ideally suited for downloading firmware, but more because the Sun Download Center is particularly not well-suited for that purpose. There is also a long history of releasing Sun firmware via SunSolve, so until there is a clearly better alternative, Sun chooses to continue with the traditional SunSolve channel.

This is an often misunderstood concept! The term "patch" has dual meanings:

• In the Solaris OS, a "patch" is a way of changing a small section of a release, without replacing the whole thing.
• A SunSolve "patch" is just a term for describing anything that is delivered through the SunSolve site.

So, while all Solaris patches are delivered through a SunSolve patch (with a patch-ID as an identifier), not all SunSolve patches deliver things that are actually Solaris patches. In fact, a SunSolve patch could be a simple text file with a favorite cake recipe (to use a silly example). There is no limitation on the type, number or purpose of "thing" released by a given SunSolve patch-ID.

So, in the case of Sun firmware, each release is a complete, self-contained and fully functional image that completely replaces the image being upgraded. There is no such thing as a partial upgrade when it comes to Sun firmware. Thus, for each separate SunSolve-based release, Sun packages up a tar file, including a README, various legal and documentation support files, the complete binary replacement image, and often the Solaris utility used to download the release to your target system. Sun never releases anything less than a complete fully functional firmware image, so the first definition of "patch" listed previously has no meaning for Sun firmware.

However, since Sun releases through the SunSolve channel, Sun is constrained to use the SunSolve standard terminology and refer to a Sun firmware release through its SunSolve "Patch-ID."

The Install.info file included with each firmware release provides information on how to determine what firmware component revisions are installed on your Sun system.

Sun provides firmware patches for free downloading at the SunSolve site. You might be required to register and create a login account before obtaining access to SunSolve.

SunSolve patch-IDs consist of a 6-digit number followed by a dash and a two-digit number (XXXXXX-YY). The 6-digit number is the base number of the patch, and the two-digit number (YY) is the revision of that patch. Each new patch-ID always starts with version -01.

For most OBP and Sun System Firmware (SysFW) releases, Sun dedicates a single SunSolve base patch-ID to a single MINOR release family of a single server system. For example, the Sun Fire T1000 server has had releases spanning six minor versions, as shown in Table 1.

Table 1: Sun Fire T1000 Server Minor Versions

Sun Fire T1000 SysFW Minor Releases	SunSolve Patch Base ID
SysFW 6.1.x	122431-xx
SysFW 6.2.x	123481-xx
SysFW 6.3.x	124751-xx
SysFW 6.4.x	126400-xx
SysFW 6.5.x	127577-xx
SysFW 6.6.x	136928-xx
SysFW 6.7.x	139435-xx

Although several other server systems have released SysFW 6.7 versions, no other server uses the 139435 base patch-ID except the Sun Fire T1000 server.

Furthermore, for a given MINOR release family, a given system might have released several MICRO versions, usually to fix important bugs. When a new MICRO version is released, Sun uses the same base patch-ID and just increments the patch version (for example, 01 is incremented to 02). For example, the Sun Fire T1000 server has released three MICRO versions of SysFW 6.5, as shown in Table 2.

Table 2: Sun Fire T1000 Server Micro Versions

Sun Fire T1000 SysFW 6.5 Micro Versions	SunSolve Patch-ID
SysFW 6.5.3	127577-01
SysFW 6.5.5	127577-02
SysFW 6.5.11	127577-03

Note that the micro versions are not consecutive (6.5.3, 6.5.5, 6.5.11) for the Sun Fire T1000 server. This is because the SysFW versioning is relative to the firmware itself, not the system, and Sun does not release every version of SysFW on every system. So, it is not unusual for consecutive micro releases for a given system to skip several MICRO version numbers. That said, consecutive MICRO versions for a given system do have consecutive SunSolve patch versions, as seen in Table 2.

This table summarizes the current releases of firmware for Sun SPARC systems.

You can also search the SunSolve Knowledgebase for your Sun system's product name along with the keyword "Hardware/PROM" to find the firmware patches that are applicable to your system. There might be several different firmware patches available for a particular system. For example, the Sun Fire T2000 server has had multiple firmware minor releases (6.1.x, 6.2.x, 6.3.x, 6.4.x, 6.5.x, 6.6.x and 6.7.x). Each of these 6.x minor releases is given a unique patch-ID number and each 6.x.y micro release becomes a subsequent revision of the patch.

Here is an example of the available firmware patches for the Sun Fire T2000 system:

• Patch 139434-01 System Firmware 6.7.0 (current patch revision of the 6.7.x minor release)
• Patch 136927-03 System Firmware 6.6.7 (current patch revision of the 6.6.x minor release)
• Patch 127576-03 System Firmware 6.5.11 (current patch revision of the 6.5.x minor release)
• Patch 126399-02 System Firmware 6.4.6 (current patch revision of the 6.4.x minor release)
• Patch 124750-08 System Firmware 6.3.12 (current patch revision of the 6.3.x minor release)
• Patch 123482-03 System Firmware 6.2.6 (current patch revision of the 6.2.x minor release)
• Patch 122430-06 System Firmware 6.1.13 (current patch revision of the 6.1.x minor release)

The Sun System Handbook and the BigAdmin Hardware Compatibility Lists (HCL) also provide information on available firmware patch updates for your Sun systems.

You can always upgrade to new firmware, but downgrades are not guaranteed. Whether they work or not depends on whether your system's hardware configuration and the rest of the software stack (the Solaris OS, patches, and so on) have any dependencies on your newer firmware. If there are dependencies and you downgrade, you might find yourself unable to even boot. So in general, downgrades should be avoided unless you know for sure your compatibility matrix is verified. Also, it should be obvious that downgrading might cause you to lose features or functionality. For example, LDoms 1.0.1 requires System Firmware release 6.5.x. Downgrading to 6.4.6 would break LDoms functionality.

The instructions for flashing the new firmware onto your system are contained in the patch Install.info file. The system needs to be powered off to flash update the firmware.