From 5838b447f675444b154bacd205ebf9f47d003b2f Mon Sep 17 00:00:00 2001 From: Marti Bolivar Date: Wed, 6 Jun 2012 18:06:48 -0400 Subject: Rework linker scripts. Having separate linker scripts for all the boards is a bad idea. Most boards really only need to specify MEMORY and the appropriate REGION_ALIASES() so that support/ld/common.inc can do its work. Not having infrastructure for this leads to duplication -- viz. the Maple Mini linker scripts are identical to the Maple's, and the olimex_stm32_h103 linker directory is just a symlink to Maple's. Clearly, the current structure is wrong. To fix it, instead of having per-board subdirectories of support/ld/, add per-MEMORY subdirectories of (new) support/ld/stm32/mem/. The per-board .mk files under support/mk/board-includes/ now reference these directly, and target-config.mk and the Makefile handle this appropriately. We move some other stuff around in target-config.mk to make this all more convenient, and even allow more overriding of the libmaple defaults on a per-board basis. Custom board hacks will be easier now. Unfortunately, lots of duplication under support/ld/stm32/mem/ is necessary, as the LENGTH attribute in a MEMORY region specification doesn't support arithmetic expressions, and ld doesn't seem to have any way to specify MEMORY at the command line (why?!). If we find a better way than this, we should do it. If a board (e.g. Maple Native) _does_ really need special memory-related configuration, you can always put a per-board subdirectory of support/ld/stm32/mem. We do this here to configure the heap. Signed-off-by: Marti Bolivar --- support/ld/ram.ld | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 support/ld/ram.ld (limited to 'support/ld/ram.ld') diff --git a/support/ld/ram.ld b/support/ld/ram.ld new file mode 100644 index 0000000..34b468e --- /dev/null +++ b/support/ld/ram.ld @@ -0,0 +1,25 @@ +/* + * libmaple linker script for RAM builds. + * + * A Flash build puts .text, .rodata, and .data/.bss/heap (of course) + * in SRAM, but offsets the sections by enough space to store the + * Maple bootloader, which uses low memory. + */ + +/* + * This pulls in the appropriate MEMORY declaration from the right + * subdirectory of stm32/mem/ (the environment must call ld with the + * right include directory flags to make this happen). Boards can also + * use this file to use any of libmaple's memory-related hooks (like + * where the heap should live). + */ +INCLUDE mem-ram.inc + +/* Provide memory region aliases for common.inc */ +REGION_ALIAS("REGION_TEXT", ram); +REGION_ALIAS("REGION_DATA", ram); +REGION_ALIAS("REGION_BSS", ram); +REGION_ALIAS("REGION_RODATA", ram); + +/* Let common.inc handle the real work. */ +INCLUDE common.inc -- cgit v1.2.3