CN106200847A - A method for realizing Clear CMOS function on ARM platform - Google Patents

Abstract

The invention discloses a method for realizing the Clear CMOS function on an ARM platform, and relates to the field of ARM servers. When the system cannot be started normally, a command is given to the BMC through an IPMITOOL tool, and a CLEAR CMOS mark is set in the BMC; Take this flag in the BMC, if the flag of CLEAR CMOS is set, the BIOS will store this flag in the variable of the FLASH ROM, and then after the BIOS triggers the system to restart, the BIOS will read the value of the variable in the FLASH ROM, if If it is set, the action of loading the default values of all variables in the FLASH ROM. The invention is novel in conception and simple in implementation, can realize the Clear CMOS function on the ARM platform, and has good practical value.

Description

A method for realizing Clear CMOS function on ARM platform

technical field

The invention relates to the field of ARM servers, in particular to a method for realizing Clear CMOS functions on an ARM platform.

Background technique

CMOS refers to a storage area on the Intel X86 platform PCH (formerly called the South Bridge). Since in the era of LEGACYBIOS, the value of the BIOS SETUP variable exists in this area, and the functions involved in this area are more critical in the previous design. . The password set by the BIOS also exists in this area, so this area is very important. With the application of UEFI BIOS, the function of this area of CMOS is weakened, most of the values of BIOS SETUP variables are no longer stored here, most of them are stored in the BIOS FLASH ROM chip of the motherboard, and only a small part is still stored in this area.

There is a CLEAR CMOS function in the previous design, there is a clear cmos jumper on the motherboard, short the jumper, or unplug the battery on the motherboard (the CMOS area is powered by a battery), the settings in the CMOS will change back to the default value . The CLEAR CMOS function is very useful. For example, the user enters the BIOS SETUP, changes some settings in it, saves and restarts the system. At this time, due to some modification errors, the system may not be able to boot. At this time, if there is no CLEAR CMOS function, the user can only repair the system by reflashing the BIOS, but reflashing the BIOS is a dangerous action for the user, and it is also troublesome, so CLEAR CMOS is more useful.

Since the CMOS function in UEFI BIOS is rarely used, this function is also realized by software simulation in UEFI BIOS, that is, after the BIOS program is cleared to CMOS, it will automatically go to the FLASH ROM to change the value of BIOS SETUP back to the default value, so that It has reached the function of the previous CMOS CLEAR. But in the ARM platform, take Cavium ARM as an example, it does not have this design in the CMOS area, nor does it have a circuit to detect CMOSCLEAR, but the CLEAR CMOS function is still necessary for BIOS security, and the Clear CMOS function needs to be implemented on the ARM platform .

Contents of the invention

The invention provides an ARM platform and a method for realizing the Clear CMOS function on the ARM platform aiming at the needs and deficiencies of the current technical development.

A kind of ARM platform of the present invention realizes the method for Clear CMOS function, the technical scheme that solves the above-mentioned technical problem adopts is as follows: described a kind of ARM platform realizes the method for Clear CMOS function, when system can't start normally, give BMC by IPMITOOL tool Issue a command to set the CLEAR CMOS logo in the BMC; BIOS reads the logo in the BMC during the boot process, if the CLEAR CMOS logo is set, the BIOS stores the logo in the variable of the FLASH ROM, and then After the BIOS triggers the system restart, the BIOS reads the value of this variable in the FLASH ROM, and if it is set, loads the default value of all variables in the FLASH ROM.

Preferably, the method for realizing the Clear CMOS function on the ARM platform, the specific implementation steps include: 1) using the IPMITOOL tool to set the FLAG1 defined by the OEM in the BMC and agreed with the BIOS; 2) booting the BIOS to read FLAG1, according to FLAG1 3) System restart; 4) BIOS to read Variable1, if it is 1, load the default values of all variables.

Preferably, in the step 2), the BIOS starts to read FLAG1, and determines whether to set Variable1 according to the value of FLAG1: if FLAG1 is 0, then set Variable1 to 0, if FLAG1 is 1, then set Variable1 to 1.

Preferably, in the step 3), if FLAG1 is 1, the system restarts.

Preferably, in the step 4), the BIOS reads Variable1, if it is 1, loads the default values of all variables, and then continues the boot process; if it is zero, does not load the default values of variables, and continues the boot process.

Compared with the prior art, the method for realizing the Clear CMOS function on the ARM platform of the present invention has the beneficial effect that: the present invention realizes the Clear CMOS function on the ARM platform without adding additional hardware circuits, and overcomes the problems of the prior art. The ARM platform is difficult to realize the defect of Clear CMOS function; moreover, the method is novel in design, simple in implementation, and convenient in operation, so it has good practical promotion value.

Instructions attached

Accompanying drawing 1 is the implementation flowchart of the method that described ARM platform realizes Clear CMOS function.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, the method for realizing the Clear CMOS function of an ARM platform described in the present invention will be further described in detail below in conjunction with specific embodiments.

A method for realizing the Clear CMOS function on an ARM platform provided by the present invention, when the system cannot be started normally, an order is given to the BMC through the IPMITOOL tool, and the CLEAR CMOS mark is set in the BMC; BIOS waits for a communication channel with the BMC during the start-up process If the CLEAR CMOS flag is set, the BIOS will store this flag in the variable of the FLASH ROM, and then the BIOS will trigger the system to restart, and then the BIOS will read the FLASH ROM If the value of this variable is set, the default value of all variables in the FLASH ROM will be loaded.

In the method for realizing the Clear CMOS function of the ARM platform, the reason why the logo of the BMC is not read to determine whether to load the default value when the first boot is started is because the BIOS and the BMC establish a channel after the BIOS boots. At that time, it will be too late to load the default value of the variable; the method is to record the BMC logo in a variable, and then read the variable to load the default value at the next restart, so that the value of the read variable can be read at POST to boot It can be done very early on.

Example:

The method for realizing the Clear CMOS function on the ARM platform described in this embodiment, when the user changes the BIOS SETUP option, or when the system fails to start normally due to other operations, its specific implementation steps include:

1) Use the IPMITOOL tool to set the FLAG1 defined by the OEM in the BMC and agreed with the BIOS; 2) The BIOS starts to read FLAG1, and decides whether to set Variable1 according to the value of FLAG1; 3) Restart the system; 4) Read the BIOS Variable1, if it is 1, load the default value of all variables.

In the step 2), the BIOS starts to read FLAG1, and determines whether to set Variable1 according to the value of FLAG1: if FLAG1 is 0, then set Variable1 to 0, if FLAG1 is 1, then set Variable1 to 1. In the step 3), if FLAG1 is 1, the system restarts. In the step 4), the BIOS reads Variable1, if it is 1, loads the default values of all variables, and then continues the boot process; if it is zero, does not load the default values of variables, and then continues the boot process.

Accompanying drawing 1 is the implementation flowchart of the method that described ARM platform realizes Clear CMOS function, as shown in accompanying drawing 1, its specific implementation process is as follows:

1) Power on the system;

2) The user decides whether to use IPMITOOL to set FLAG1 defined by the OEM in the BMC and agreed with the BIOS according to the needs;

3) BIOS starts to read FLAG1;

4) Determine whether FLAG1 = 1 or not;

5) If FLAG1 is 1, set Variable1, set FLAG1 to zero, and restart the system;

6) If FLAG1 is not 1, continue the boot process;

7) After step 5), the BIOS starts to read Variable1;

8) Determine whether Variable1= 1 or not;

9) If Variable1=1, then set Variable1 to zero and load the default values of all variables; continue the boot process;

10) If Variable1 is not 1, continue the boot process.

The above-mentioned specific embodiments are only specific cases of the present invention, and the scope of patent protection of the present invention includes but is not limited to the above-mentioned specific embodiments, any claims that meet the claims of the present invention and any ordinary skilled person in the technical field. Appropriate changes or substitutions should fall within the scope of patent protection of the present invention.

Claims (5)

1. the method that an ARM platform realizes Clear CMOS function, it is characterised in that when system cannot normal boot-strap time, logical Cross IPMITOOL instrument to issue orders to BMC, the mark of set CLEAR CMOS in BMC；BIOS reads BMC in start process In this mark, if the mark of CLEAR CMOS is set, then BIOS leaves FLASH ROM's in this mark In variable, after then BIOS triggers system reboot, BIOS goes to read the value of this variable in FLASH ROM, if There is set, then load the action of the default value of all variable in FLASH ROM.

A kind of method that ARM platform realizes Clear CMOS function, it is characterised in that described ARM platform realizes the method for Clear CMOS function, and it implements step and includes: 1) with in IPMITOOL instrument set BMC The FLAG1 appointed with BIOS of OEM definition；2) BIOS start goes to read FLAG1, decides whether to put according to the value of FLAG1 Position Variable1；3) system reboot；4) BIOS goes to read Variable1, if 1, then load the acquiescence of all variable Value.

A kind of method that ARM platform realizes Clear CMOS function, it is characterised in that described step Rapid 2), in, BIOS start goes to read FLAG1, decides whether set Variable1 according to the value of FLAG1: if FLAG1 is 0, then Set Variable1 as 0, if FLAG1 is 1, then set Variable1 as 1.

A kind of method that ARM platform realizes Clear CMOS function, it is characterised in that described step Rapid 3) in, if FLAG1 is 1, system reboot.

A kind of method that ARM platform realizes Clear CMOS function, it is characterised in that described step Rapid 4), in, BIOS goes to read Variable1, if 1, then load the default value of all variable, then proceed to boot program； If zero, the most do not carry out loading the default value of variable, continue boot program.