What is bss data section?

What is bss data section?

In computer programming, the block starting symbol (abbreviated to . bss or bss) is the portion of an object file, executable, or assembly language code that contains statically allocated variables that are declared but have not been assigned a value yet. It is often referred to as the “bss section” or “bss segment”.

What is the use of bss section?

bss section is used by the compiler for global and static variables. It is one of the default COFF sections that is used to reserve a specified amount of space in the memory map that can later be used for storing data. It is normally uninitialized. All global and static variables in a C program are placed in the .

What is the difference between data and bss section?

What is the difference between the Data and BSS sections? BSS refers to uninitialized global and static objects and Data refers to initialized global and static objects. Both BSS and Data usually refer to RAM objects. The .

What is text bss and data?

‘text’ is my code, vector table plus constants. ‘data’ is for initialized variables, and it counts for RAM and FLASH. The linker allocates the data in FLASH which then is copied from ROM to RAM in the startup code. ‘bss’ is for the uninitialized data in RAM which is initialized with zero in the startup code.

What is uninitialized data?

An uninitialized variable has an undefined value, often corresponding to the data that was already in the particular memory location that the variable is using. This can lead to errors that are very hard to detect since the variable’s value is effectively random, different values cause different errors or none at all.

What is BSS in size?

bss and add almost nothing (about 4–8 bytes for the description) to the executable file size. So the reason for . bss is to have smaller executable, saving space and allowing faster loading of the program, as the loader(startup) can just allocate a bunch of zeros instead of having to copy the data from disk. So .

Why do we initialize and uninitialized data segment?

The initialized data segment contains global and static variables that are explicitly initialized. The values of these variables are read from the executable file when the program is loaded into memory. The uninitialized data segment contains global and static variables that are not explicitly initialized.

What is bss section in Linker?

bss section. This section contains zeroed bytes when your program begins running. It is used to hold uninitialized variables or common storage.

Is BSS stored in RAM?

Uninitialized variables are stored in bss section. In embedded software, the bss segment is mapped into memory that is initialized to zero by the C run-time system before main() is entered. Data and bss segments occupy the RAM area as below. bss section is not modified.

Is bss section in the heap?

How does the computer remember where these segments are? Especially heap, since bss is directly after data, but heap often is placed a different place in memory.

What is initialized and uninitialized data?

Why is BSS not in a out?

a. out contains the bss segment in its segment table, which includes the length and offset of that segment. But bss segments do not require any data, since they are initialized to 0 by the loader, so there is no corresponding data in the executable file.

What is data section?

In computing, a data segment (often denoted . data) is a portion of an object file or the corresponding address space of a program that contains initialized static variables, that is, global variables and static local variables.

Where is initialized data stored?

Initialised data is not stored in non volatile memory while the process is running but it goes along with rest of segments in RAM.

Which variables are stored in bss?

Uninitialized variables are stored in bss section.

Is bss stored in RAM?

Where does the uninitialized data gets stored in memory?

24. Where does the uninitialized data gets stored in memory? Explanation: BSS- Block started by symbol the uninitialized data gets stored in memory.

What is data initialization?

Initialization is the process of locating and using the defined values for variable data that is used by a computer program. For example, an operating system or application program is installed with default or user-specified values that determine certain aspects of how the system or program is to function.

What does initialization mean?

: to set (something, such as a computer program counter) to a starting position, value, or configuration.