.build_info (0x3c0f5144) : { KEEP(*(.build_info)) . = ALIGN(4); } > FLASH = 0x00000000 what is the difference between 0x3c0f5514 and 0x00000000? why is the latter address the starting address of the entire program? give me actual linker script examples?

In the provided linker script snippet, `0x3c0f5514` is the memory address where the `build_info` section will be stored in the FLASH memory, whereas `0x00000000` is the starting address of the entire program in the FLASH memory.

The `build_info` section is typically used to store build information such as the version number, build date/time, and other metadata about the program. It is not part of the executable code and is generally not used during program execution.

The reason `0x00000000` is the starting address of the entire program is because this is typically the address where the program's reset vector is located. The reset vector is the first instruction that is executed when the microcontroller is powered on or reset. By convention, the reset vector is located at the beginning of the program memory, which is why `0x00000000` is the starting address.

Here is an example linker script snippet that demonstrates how these memory regions can be defined:

MEMORY
{
    FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 1M
    RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 128K
}

SECTIONS
{
    .text :
    {
        *(.vector_table)
        *(.text)
    } > FLASH

    .data :
    {
        *(.data)
    } > RAM AT > FLASH

    .bss :
    {
        *(.bss)
    } > RAM
}

In this example, the `FLASH` memory region starts at address `0x00000000` and has a length of `1M`. The `RAM` memory region starts at address `0x20000000` and has a length of `128K`.

The `SECTIONS` block then defines where different sections of the program will be located in memory. For example, the `.text` section contains the program code and is located in the `FLASH` memory region. The `.data` section contains initialized data and is located in the `RAM` memory region, but is also copied to the `FLASH` memory region. The `.bss` section contains uninitialized data and is located in the `RAM` memory region.