The Boot Process (Reference)
This chapter describes the firmware used for booting SPARC based and IA based systems. This chapter also provides an overview of the boot process on each platform.
This is a list of the reference information in this chapter.
For step-by-step instructions on booting a system, see Chapter 13, SPARC: Booting a System (Tasks) or Chapter 14, IA: Booting a System (Tasks).
SPARC: The Boot PROM
Each SPARC based system has a PROM (programmable read-only memory) chip with a program called the monitor. The monitor controls the operation of the system before the Solaris kernel is available. When a system is turned on, the monitor runs a quick self-test procedure to checks the hardware and memory on the system. If no errors are found, the system begins the automatic boot process.
Note - Some older systems might require PROM upgrades before they will work with the Solaris system software. Contact your local service provider for more information.
SPARC: The Boot Process
The following table describes the boot process on SPARC based systems.
Table 15-1 SPARC: Description of the Boot Process
Boot Phase | Description |
|---|---|
Boot PROM | 1. The PROM displays system identification information and then runs self-test diagnostics to verify the system's hardware and memory. |
| 2. Then, the PROM loads the primary boot program, bootblk, whose purpose is to load the secondary boot program (that is located in the ufs file system) from the default boot device. |
Boot Programs | 3. The bootblk program finds and executes the secondary boot program, ufsboot, and loads it into memory. |
| 4. After the ufsboot program is loaded, the ufsboot program loads the kernel. |
Kernel Initialization | 5. The kernel initializes itself and begins loading modules by using ufsboot to read the files. When the kernel has loaded enough modules to mount the root (/) file system, the kernel unmaps the ufsboot program and continues, using its own resources. |
6. The kernel creates a user process and starts the /sbin/init process, which starts other processes by reading the /etc/inittab file. | |
init | 7. The /sbin/init process starts the run control (rc) scripts, which execute a series of other scripts. These scripts (/sbin/rc*) check and mount file systems, start various processes, and perform system maintenance tasks. |
IA: The PC BIOS
Before the kernel is started, the system is controlled by the read-only-memory (ROM) Basic Input/Output System (BIOS), which is the firmware interface on a PC.
Hardware adapters can have an on-board BIOS that displays the physical characteristics of the device and can be used to access the device.
During the startup sequence, the PC BIOS checks for the presence of any adapter BIOS, and if found, loads and executes each adapter BIOS. Each individual adapter's BIOS runs self-test diagnostics and displays device information.
IA: Boot Subsystems
At three points during the Solaris boot process, you can make the following choices about a booting system as follows:
Primary Boot Subsystem (Partition Boot Menu) - This first menu appears if multiple operating environments exist on the disk. The menu enables you to boot any of the operating environments installed. By default, the operating environment that is designed as active is booted.
Note that if you choose to boot a non-Solaris operating environment, you cannot reach the next two menus.
Interrupt the Autoboot Process - If the autoboot process is interrupted, you can access the Solaris Device Configuration Assistant.
The Solaris Device Configuration Assistant enables you to boot the Solaris system from a different boot device, configure new or misconfigured hardware, or perform other device-related or boot-related tasks.
Current Boot Parameters Menu - Two forms of this menu exist, one for a normal Solaris boot and one menu for a Solaris installation boot:
The normal Current Boot Parameters menu enables you to boot the Solaris system with options, or enter the boot interpreter.
The install Current Boot Parameters menu enables you to select the type of installation to be performed, or customize the boot.
The following table summarizes the purpose of the primary IA boot interfaces. See the sections that follow for a detailed description and example of each boot interface.
Table 15-2 IA: Boot Subsystems
Boot Subsystem | Purpose |
|---|---|
Primary Boot Subsystem | This menu appears if the disk you are booting from contains multiple operating environments, including the Solaris operating environment. |
Secondary Boot Subsystem | This menu appears each time you boot the Solaris release. The Solaris release is booted automatically unless you choose to run the Solaris Device Configuration Assistant by interrupting the autoboot process. |
Solaris Device Configuration Assistant/Boot Diskette | There are two ways to access the Solaris Device Configuration Assistant menus:
|
Current Boot Parameters Menu | This menu appears when you boot the Solaris release from the disk, CD-ROM, or the network. The menu presents a list of boot options. |
Note - If you need to create the Solaris Device Configuration Assistant boot diskette, go to http://soldc.sun.com/support/drivers/dca_diskettes.
During the boot process, the boot subsystem menus allow you to customize boot choices. If the system receives no response during the time-out periods, it continues to boot automatically using the default selections. You can stop the boot process when each boot subsystem menu is displayed. Or, you can let the boot process continue automatically.
The following section provides examples of each boot subsystem screen.
IA: Booting the Solaris Release
During the device identification phase, the Solaris Device Configuration Assistant does the following:
Scans for devices that are installed on the system
Displays the identified devices
Enables you to perform optional tasks such as selecting a keyboard type and editing devices and their resources
During the boot phase, the Solaris Device Configuration Assistant does the following:
Displays a list of devices from which to boot. The device marked with an asterisk (*) is the default boot device.
Enables you to perform optional tasks, such as editing autoboot settings and property settings, and choosing the network configuration strategy.
The following section provides examples of menus that appear during the device identification phase. The device output varies based on your system configuration.