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Sco-Unix core of the boot process

Posted 2012-05-03 21:15:55 by admin

Unix either from the hard disk and can boot from a floppy disk. Both are loaded by the BIOS hard disk or floppy disk boot sector, boot sector to load the implementation of the core bootloader?? The Boot program. This article briefly describes the boot process of the Boot program.

Boot internal command

the Boot? "" systty "," mem "," dir "," link "a total of five internal command. Sco Unix 5.0 above there are "debug", "version" two commands.

1)? : On the command line, enter "?" To display the Boot can load the equipment of the Unix kernel, cases:

fd: Floppy, hd: the hard disk. fd is (61): the correspond able to boot the first floppy disk, hd (40): corresponds to the first hard disk to guide. Sco-Unix-5.0 or later, you can also start the Unix-on

2) systty = 0 or 1:

at system boot time, the hdboot1 to confirm the primary display adapter and com1 validity. In default mode, the console is located in the main adapter, host adapter failure is not available, the system automatically com1 port as the main console. Modify Location the through systty parameter systty = 0: The console is located on the host adapter systty = 1: The console is located on the com1 port. The default communication parameters: 9600 baud, 8 bits, 1 stop bit, no parity.

3) mem = [range] [/ flag]:

In general, the Boot is able to detect all the system memory, you can use the "mem =/p" to display memory. If the Boot detect memory errors, or for special needs, you can use this parameter to adjust the system memory available. This is a major feature of the Unix system.

range: the range of memory


starting memory? end of memory

the end of the memory? starting memory/d

starting memory + memory size

memory unit with the k-(kilobytes) and m (megabytes). Example:

1m? 8m, or 8m? 1m/d, or 1024k? 8m: that the system can be used to 8m memory. Another:

1m? 5m, 6m? 8m: System 8m memory, 5m? the 6m memory can not be used.

the flag logo, the following forms:

/d: high address to low address scanning.

/n: indicate the segment of memory access for non-DMA mode, other than the all 16M memory, the system automatically marked as non-DMA mode.

/r: a dedicated memory segment. If the segment of memory Rom, Shadowing, this section of memory is identified as a special segment covered to prevent the Boot and the Unix kernel. In addition to the Shadow Rom, the other can be run independently of the program text segment can also be placed in a special paragraph.

/l: Unix core of the body to be placed below the 16m memory.

/p: Displays the Boot initial detection to memory, or after the mem parameter adjustment, has once again proven to the memory.

is, the adjustment of the above parameters must be other than 1M of memory. Boot memory outside of the hole can not be detected if the memory hole exists in the memory. On many machines, Unix can not deal with the problem of Rom, Shadowing must be disabled in the settings of the machine. Sometimes, we may find that some models of the machine Rom, Shadowing, and Unix-still work properly, because Boot boot automatically machine Rom Shadowing ban out.

4) dir: View current Boot device file system directory.

5) the link: Unix kernel is loaded into the device driver (called BTLD program).

format 1: Boot command prompt, type "link" Enter, the system prompts:

what the packages do you need linked into the system,

or q to quit?:

after ":", input BTLD name separated by a space between multiple BTLD, according to the system prompt, insert corresponding BTLD panel.

format 2: Boot command prompt, type: link = "of the BTLD name 1 the BTLD name 2 ..."


the BTLD names separated by spaces and enclosed in quotation marks.

Boot external executable

external executable program in

Boot is out of the Unix kernel code can run independently of the program. In general, these programs are written in assembler, machine code, such as: dos, Bootos and so on.

Boot prompt, the input dos or Bootos, dos you can make the system go to the dos operating system. In addition to the DOS bootable system: the various versions of DOS system (dos_12, dos_16 dos_32, dos_ext), for Windows, the Novell, NT,, OS2, OS2_hpfs, picx, xenix, ccpm and Unix, etc.. The format is:

Bootos sysname

(of which: sysname for the above system name)

Unix-start default configuration

If the Boot command line prompt: "Direct Enter, Boot to start the default kernel to initialize the default system environment. These default placed in/etc/default/boot file. The common parameters are as follows:


AUTOBOOT = Yes or NO if AUTOBOOT = Yes, Boot prompt appears: "do not have any input, the TIMEOUT defined, loaded automatically by the DEFBOOTSTR defined in the Unix kernel. By default, AUTOBOOT = No.

the TIMEOUT = SECONDS system without human intervention in the event of a prompt, the system should wait for the number of seconds, the system input as a carriage return. By default, the TIMEOUT = 60.

parameter table Standalone

DEFBOOTSTR = standalone program can be run independently. The core of the definition of system default boot name.

RONLYROOT = Yes or No. RONLYROOT = Yes, the root file system is installed as read-only state. The default is No..

SYSTTY = 0 or 1 to 0, the console is located on the primary display adapter. 1, is on COM1. Default in the main display adapter.

the SERIAL = parameter 1, parameter 2, ... as defined in the console communication parameters. Example: SERIAL = 9600,8,1, N-port communication baud rate to 9600, the byte width of 8, stop bits for a non-parity.

In addition, the shared parameters and IN99v:


the core of the self-adjustment

Unix kernel boot Boot can pass parameters to the core. The specific usage:

Sco Unix System V/386


: unix = value

The available parameters are:

kernel.root = device

root file system default in hd (40) can be located through the device, other devices.

kernel.swap = device

definition of the initial swap area, the default hd (40).

kernel.swplo = s

defined paging block 0 the location of the swap area, the default block location began in the swap area.

kernel.nswap = n

define the size of the paging block. At this point, the actual location of the paging block s to s + n-1.

core to start automatically, not manual intervention.


the root file system read-only state.

kernel.hd = xnamex

definition of the primary hard disk device driver.

boot process to display the help

correctly guide the Boot, the system will prompt:

Sco Unix System V/386



description system is currently under the control of the interactive program Boot ":" for its command-line prompt. In the prompt, you can enter the internal command, Unix or other can be run independently of the program (standalone).

----------------------------------------------- ---------------------------------

, Sco-Unix-error message comment


IO ERR: Can not find the active partition.

the OVF:

CLY outside of the operating system in 1024 cylinders of the hard disk master boot program can not load the partition boot block.

BAD, the TBL: partition table is marked with two or more of the active partition.

NO OS: there is no active partition or active partition boot block can not be loaded to run.

hdboot0 bootloader error message?

can not open: Can not find the/boot.

of Bad param :/ boot parameter error.

the stage 1 the boot failure :/ boot can not find file error, and required system disk to start the machine.

hdboot1 bootloader error message?

bad the magic number: the type of program can not run.

can not open: file not found.

the COFF files not supported as a standalone programs: the program can not run independently, need kernel support.

the Command line too long - the aborting: the boot command line length is 256 bytes...

Note: Have you found this article is fulled of spelling and grammatical errors? Yeah, it was translated by machine, but if you found it worth reading, please click the "Rate" button below to vote it. When it received 20 votes or more, it will be put to a library and waited for a manual translation. If you can read Chinese, check the original posts here: Sco-Unix core of the boot process

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