Re: [PATCH v3 1/5] xen: define ACPI and DT device info sections macros

[oleksii.kurochko@xxxxxxxxx]

On Wed, 2024-09-25 at 10:36 +0200, Jan Beulich wrote:
> PPC's desire to use DECL_SECTION() can certainly be covered by
> providing
> a (trivial) DECL_SECTION() also for Arm and RISC-V. Seeing that even
> x86
> overrides the default to the trivial form for building xen.efi, I'm
> inclined to suggest we should actually have a way for an arch to
> indicate
> to xen.lds.h that it wants just the trivial form (avoiding a later
> #undef).
If to go with what I suggested before then x86 will look like:

diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
index d48de67cfd..911585541e 100644
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -3,6 +3,10 @@
 
 #include <xen/cache.h>
 #include <xen/lib.h>
+
+#ifdef EFI
+#define SIMPLE_DECL_SECTION
+#endif
 #include <xen/xen.lds.h>
 #include <asm/page.h>
 #undef ENTRY
@@ -12,9 +16,7 @@
 
 #define FORMAT "pei-x86-64"
 #undef __XEN_VIRT_START
-#undef DECL_SECTION
 #define __XEN_VIRT_START __image_base__
-#define DECL_SECTION(x) x :
 
 ENTRY(efi_start)
 
diff --git a/xen/include/xen/xen.lds.h b/xen/include/xen/xen.lds.h
index a17810bb28..fb11ba7357 100644
--- a/xen/include/xen/xen.lds.h
+++ b/xen/include/xen/xen.lds.h
@@ -5,6 +5,8 @@
  * Common macros to be used in architecture specific linker scripts.
  */
 
+#ifdef SIMPLE_DECL_SECTION
+
 /*
  * Declare a section whose load address is based at PA 0 rather than
  * Xen's virtual base address.
@@ -15,6 +17,10 @@
 # define DECL_SECTION(x) x : AT(ADDR(x) - __XEN_VIRT_START)
 #endif
 
+#else /* SIMPLE_DECL_SECION */
+# define DECL_SECTION(x) x :
+#endif
+
 /*
  * To avoid any confusion, please note that the EFI macro does not
correspond
  * to EFI support and is used when linking a native EFI (i.e. PE/COFF)
binary,

Does it make sense? Or it would be better to follow way for each
architecture:
   #undef DECL_SECTION
   #define DECL_SECTION(x) x :
   
~ Oleksii