conditional statements for linker command language LD

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Are there conditional statements for the GNU LD linker command language?

Context: I am developing firmware for an arm cortex m0+, which consists of a bootloader and an application. Both are compiled and flashed to target in separate projects, but I use a framework with symbolic links to the drivers, makefile and loader scripts so that I can reuse those for every app I make without copying these files for each app. Currently I have two loader files, for bootloader and application (makefile automatically specifies the appropriate one), with memory assigment as follows:

bootloader

MEMORY { 
  flash (rx)  : ORIGIN = 0x00000000, LENGTH = 16K
  ram   (rwx) : ORIGIN = 0x1FFFF000, LENGTH =  16K
}

app

MEMORY { 
  flash (rx)  : ORIGIN = 0x00004000, LENGTH = 112K
  ram   (rwx) : ORIGIN = 0x1FFFF000, LENGTH =  16K
}

Like the makefile, I want to merge these to something like this (using C expressions to clarify)

MEMORY { 
#ifdef(bootloaderSymbol)
  flash (rx)  : ORIGIN = 0x00000000, LENGTH = 16K
#else
  flash (rx)  : ORIGIN = 0x00004000, LENGTH = 112K
#endif
  ram   (rwx) : ORIGIN = 0x1FFFF000, LENGTH =  16K
}
cortex-m linker-scripts ld
3 Answers

I think you can try "DEFINED(symbol)" according to https://sourceware.org/binutils/docs/ld/Builtin-Functions.html

Also, please don't forget to pass "--defsym=bootloaderSymbol=1" to ld.

MEMORY {
    flash (rx)  : ORIGIN = DEFINED(bootloaderSymbol) ? 0x00000000 : 0x00004000, LENGTH = DEFINED(bootloaderSymbol) ? 112K : 16K
    ram   (rwx) : ORIGIN = 0x1FFFF000, LENGTH =  16K
}
user_25904910
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