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symbols: Change implementation details of DECLARE_OPTIONAL_REGION()

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It seems that GCC's LTO doesn't like the way we implement
DECLARE_OPTIONAL_REGION(). This patch changes it so that rather than
having a normal DECLARE_REGION() in <symbols.h> and then an extra
DECLARE_OPTIONAL_REGION() in the C file using it, you just say
DECLARE_OPTIONAL_REGION() directly in <symbols.h> (in place and instead
of the usual DECLARE_REGION()). This basically looks the same way in the
resulting object file but somehow LTO seems to like it better.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I6096207b311d70c8e9956cd9406bec45be04a4a2
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44791
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
This commit is contained in:
Julius Werner
2020-08-25 16:00:44 -07:00
parent 8cc80d5e50
commit 644a512e56
10 changed files with 17 additions and 31 deletions
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29
src/include/symbols.h
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@@ -13,8 +13,20 @@ extern u8 _dram[];
extern u8 _##name[]; \
extern u8 _e##name[];
/*
* Regions can be declared optional if not all configurations provide them in
* memlayout and you want code to be able to check for their existence at
* runtime. Not every region that is architecture or platform-specific should
* use this -- only declare regions optional if the code *accessing* them runs
* both on configurations that have the region and those that don't. That code
* should then check (REGION_SIZE(name) != 0) before accessing it.
*/
#define DECLARE_OPTIONAL_REGION(name) \
__weak extern u8 _##name[]; \
__weak extern u8 _e##name[];
DECLARE_REGION(sram)
DECLARE_REGION(timestamp)
DECLARE_OPTIONAL_REGION(timestamp)
DECLARE_REGION(preram_cbmem_console)
DECLARE_REGION(cbmem_init_hooks)
DECLARE_REGION(stack)
@@ -53,24 +65,15 @@ DECLARE_REGION(ramstage)
DECLARE_REGION(pagetables)
DECLARE_REGION(ttb)
DECLARE_REGION(ttb_subtables)
DECLARE_OPTIONAL_REGION(ttb_subtables)
DECLARE_REGION(dma_coherent)
DECLARE_REGION(soc_registers)
DECLARE_REGION(framebuffer)
DECLARE_REGION(pdpt)
DECLARE_REGION(opensbi)
DECLARE_REGION(bl31)
DECLARE_OPTIONAL_REGION(opensbi)
DECLARE_OPTIONAL_REGION(bl31)
DECLARE_REGION(transfer_buffer)
/*
* Put this into a .c file accessing a linker script region to mark that region
* as "optional". If it is defined in memlayout.ld (or anywhere else), the
* values from that definition will be used. If not, start, end and size will
* all evaluate to 0. (We can't explicitly assign the symbols to 0 in the
* assembly due to https://sourceware.org/bugzilla/show_bug.cgi?id=1038.)
*/
#define DECLARE_OPTIONAL_REGION(name) asm (".weak _" #name ", _e" #name)
/* Returns true when pre-RAM symbols are known to the linker.
* (Does not necessarily mean that the memory is accessible.) */
static inline int preram_symbols_available(void)