[U-Boot] [PATCH 4/4] ARM: fix CONFIG_SPL_MAX_SIZE semantics

[Albert ARIBAUD]

The ASSERT() in arch/arm/cpu/u-boot.lds is unneeded as
this linker file is not used for SPL builds. Remove it.

The ASSERT() in arch/arm/cpu/u-boot-spl.lds is wrong
as it compares image+BSS size to max image size only.
Split it in two distinct ASSERT()s, one for image size,
one for BSS size.

Finally, update README regarding the (now homogeneous)
semantics of the CONFIG_SPL_MAX_SIZE and
CONFIG_SPL_BSS_MAX_SIZE macros.

Signed-off-by: Albert ARIBAUD <albert.u.boot at aribaud.net>
---
 README                      |   17 +++++++++++++++--
 arch/arm/cpu/u-boot-spl.lds |   10 ++++++++--
 arch/arm/cpu/u-boot.lds     |    4 ----
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/README b/README
index a35ef31..c902421 100644
--- a/README
+++ b/README
@@ -2784,7 +2784,14 @@ FIT uImage format:
 		LDSCRIPT for linking the SPL binary.
 
 		CONFIG_SPL_MAX_SIZE
-		Maximum binary size (text, data and rodata) of the SPL binary.
+		Maximum size for the image (sum of the text, data, rodata
+		and linker lists sections) of the SPL executable.
+		When defined, linker checks that the actual image size does
+		not exceed it.
+		The total amount of memory used by the SPL when running is
+		equal CONFIG_SPL_MAX_SIZE, plus CONFIG_SPL_BSS_MAX_SIZE if
+		it exists.
+		Note: image and BSS are disjoint for some targets.
 
 		CONFIG_SPL_TEXT_BASE
 		TEXT_BASE for linking the SPL binary.
@@ -2797,7 +2804,13 @@ FIT uImage format:
 		Link address for the BSS within the SPL binary.
 
 		CONFIG_SPL_BSS_MAX_SIZE
-		Maximum binary size of the BSS section of the SPL binary.
+		Maximum size of the BSS section of the SPL executable.
+		When defined, linker checks that the actual BSS size does
+		not exceed it.
+		The total amount of memory used by the SPL when running is
+		equal CONFIG_SPL_MAX_SIZE, plus CONFIG_SPL_BSS_MAX_SIZE if
+		it exists.
+		Note: image and BSS are disjoint for some targets.
 
 		CONFIG_SPL_STACK
 		Adress of the start of the stack SPL will use
diff --git a/arch/arm/cpu/u-boot-spl.lds b/arch/arm/cpu/u-boot-spl.lds
index 3c0d99c..89ef9ce 100644
--- a/arch/arm/cpu/u-boot-spl.lds
+++ b/arch/arm/cpu/u-boot-spl.lds
@@ -88,6 +88,12 @@ SECTIONS
 	/DISCARD/ : { *(.gnu*) }
 }
 
-#if defined(CONFIG_SPL_TEXT_BASE) && defined(CONFIG_SPL_MAX_SIZE)
-ASSERT(__bss_end < (CONFIG_SPL_TEXT_BASE + CONFIG_SPL_MAX_SIZE), "SPL image too big");
+#if defined(CONFIG_SPL_MAX_SIZE)
+ASSERT(__image_copy_end - __image_copy_start < (CONFIG_SPL_MAX_SIZE), \
+	"SPL image too big");
+#endif
+
+#if defined(CONFIG_SPL_BSS_MAX_SIZE)
+ASSERT(__bss_end - __bss_start < (CONFIG_SPL_BSS MAX_SIZE), \
+	"SPL image BSS too big");
 #endif
diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds
index 3a1083d..7bbc4f5 100644
--- a/arch/arm/cpu/u-boot.lds
+++ b/arch/arm/cpu/u-boot.lds
@@ -101,7 +101,3 @@ SECTIONS
 	/DISCARD/ : { *(.interp*) }
 	/DISCARD/ : { *(.gnu*) }
 }
-
-#if defined(CONFIG_SPL_TEXT_BASE) && defined(CONFIG_SPL_MAX_SIZE)
-ASSERT(__bss_end < (CONFIG_SPL_TEXT_BASE + CONFIG_SPL_MAX_SIZE), "SPL image too big");
-#endif
-- 
1.7.10.4