[U-Boot] [PATCH 2/3] ARM: pxa: Fix OneNAND SPL builds

[Marek Vasut <marex@denx.de>]

The OneNAND SPL used on PXA is slightly obscure. Due to the OneNAND limitation,
where we have only the first 1KiB of the OneNAND available upon power-up as a
memory-mapped area, from which the CPU starts executing, we place only the most
essential code into this first 1KiB . This code copies the rest of the SPL into
SRAM and jumps to it. This code is stored in section .text.0 .

The rest of the SPL is stored in section .text.1 . When running the OBJCOPY on
the SPL, it will preserve only .text section, but the .text.0 and .text.1 are
stripped away from the result, thus making the SPL binary empty. The patch adds
additional -j parameters to the OBJCOPY for PXA during the SPL build, which will
preserve the .text.0 and .text.1 sections.

Moreover, this patch also adds missing functions into the .text.0 section, since
otherwise the PXA270 with 1KiB-window OneNAND won't be able to boot.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Tom Rini <trini@ti.com>
---
 arch/arm/cpu/pxa/config.mk   | 13 +++++++++++++
 board/vpac270/u-boot-spl.lds |  1 +
 2 files changed, 14 insertions(+)

diff --git a/arch/arm/cpu/pxa/config.mk b/arch/arm/cpu/pxa/config.mk
index d8d263d..f2befbe 100644
--- a/arch/arm/cpu/pxa/config.mk
+++ b/arch/arm/cpu/pxa/config.mk
@@ -14,3 +14,16 @@ PLATFORM_CPPFLAGS += -mcpu=xscale
 # ========================================================================
 PF_RELFLAGS_SLB_AT := $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))
 PLATFORM_RELFLAGS += $(PF_RELFLAGS_SLB_AT)
+
+#
+# !WARNING!
+# The PXA's OneNAND SPL uses .text.0 and .text.1 segments to allow booting from
+# really small OneNAND memories where the mmap'd window is only 1KiB big. The
+# .text.0 contains only the bare minimum needed to load the real SPL into SRAM.
+# Add .text.0 and .text.1 into OBJFLAGS, so when the SPL is being objcopy'd,
+# they are not discarded.
+#
+
+#ifdef CONFIG_SPL_BUILD
+OBJCFLAGS += -j .text.0 -j .text.1
+#endif
diff --git a/board/vpac270/u-boot-spl.lds b/board/vpac270/u-boot-spl.lds
index 02d107c..b6fdde4 100644
--- a/board/vpac270/u-boot-spl.lds
+++ b/board/vpac270/u-boot-spl.lds
@@ -20,6 +20,7 @@ SECTIONS
 	.text.0	:
 	{
 		arch/arm/cpu/pxa/start.o		(.text*)
+		arch/arm/lib/built-in.o			(.text*)
 		board/vpac270/built-in.o		(.text*)
 		drivers/mtd/onenand/built-in.o		(.text*)
 	}
-- 
1.8.4.2