[PATCH] ARM/RISC-V: pbl.lds: drop ALIGN before _text and assert entry at start

[Sascha Hauer <s.hauer@pengutronix.de>]

.image_start and ._text only hold the zero-sized __image_start and
_text markers, so the location counter is still 0 when it reaches
the ALIGN(4) in front of ._text. The ALIGN was only meaningful while
PRE_IMAGE could place data of arbitrary size there. RISC-V copied the
sequence from ARM.

The PBL must start with its entry code: it is started from its first
address, the image size is taken as __image_end, and code copying the
image uses __image_start and _text interchangeably. Assert that
instead of silently relying on it.

Assisted-by: Claude:claude-opus-5-5
---
 arch/arm/lib/pbl.lds.S   | 3 ++-
 arch/riscv/lib/pbl.lds.S | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/lib/pbl.lds.S b/arch/arm/lib/pbl.lds.S
index c4abfc5989..2c96034c4e 100644
--- a/arch/arm/lib/pbl.lds.S
+++ b/arch/arm/lib/pbl.lds.S
@@ -40,7 +40,6 @@ SECTIONS
 
 	.image_start : { *(.__image_start) }
 
-	. = ALIGN(4);
 	._text : { *(._text) }
 	.text      :
 	{
@@ -152,4 +151,6 @@ SECTIONS
 
 	_barebox_image_size = __image_end;
 	_barebox_pbl_size = __bss_start;
+
+	ASSERT(_stext == __image_start, "PBL entry code must be at the image start")
 }
diff --git a/arch/riscv/lib/pbl.lds.S b/arch/riscv/lib/pbl.lds.S
index 17cd61ff75..e580ec06f3 100644
--- a/arch/riscv/lib/pbl.lds.S
+++ b/arch/riscv/lib/pbl.lds.S
@@ -14,7 +14,6 @@ SECTIONS
 
 	.image_start : { *(.__image_start) }
 
-	. = ALIGN(4);
 	._text : { *(._text) }
 	.text      :
 	{
@@ -87,4 +86,6 @@ SECTIONS
 
 	_barebox_image_size = __image_end;
 	_barebox_pbl_size = __bss_start;
+
+	ASSERT(_stext == __image_start, "PBL entry code must be at the image start")
 }
-- 
2.47.3