[PATCH 15/19] ARM: link ELF image into PBL

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

Instead of linking the raw binary barebox proper image into the PBL link
the ELF image into the PBL. With this barebox proper starts with a properly
linked and fully initialized C environment, so the calls to
relocate_to_adr() and setup_c() can be removed from barebox proper.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/Kconfig          |  2 ++
 arch/arm/cpu/start.c      |  4 ----
 arch/arm/cpu/uncompress.c | 32 ++++++++++++++++++++++++++------
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index afa6de3cd0b145e42755e3ca2d7a13c8a69ff1d3..60975083b32f3127f982c526c6cf30ffe3e45924 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -17,6 +17,8 @@ config ARM
 	select HAVE_ARCH_BOOTM_OFTREE
 	select HW_HAS_PCI
 	select ARCH_HAS_DMA_WRITE_COMBINE
+	select ELF
+	select PBL_IMAGE_ELF
 	default y
 
 config ARCH_LINUX_NAME
diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
index f7d4507e71588ba5e241b24b952d55e2a4b0f794..71a12abdd0941889617e6b63063304d0e4522c81 100644
--- a/arch/arm/cpu/start.c
+++ b/arch/arm/cpu/start.c
@@ -139,10 +139,6 @@ __noreturn __prereloc void barebox_non_pbl_start(unsigned long membase,
 	if (IS_ENABLED(CONFIG_CPU_V7))
 		armv7_hyp_install();
 
-	relocate_to_adr(barebox_base);
-
-	setup_c();
-
 	barrier();
 
 	pbl_barebox_break();
diff --git a/arch/arm/cpu/uncompress.c b/arch/arm/cpu/uncompress.c
index b9fc1d04db96e77c8fcd7fd1930798ea1d9294d7..ccc3c5ae3ba60e990ee73715a49a316e2a14c44e 100644
--- a/arch/arm/cpu/uncompress.c
+++ b/arch/arm/cpu/uncompress.c
@@ -20,6 +20,7 @@
 #include <asm/mmu.h>
 #include <asm/unaligned.h>
 #include <compressed-dtb.h>
+#include <elf.h>
 
 #include <debug_ll.h>
 
@@ -85,21 +86,40 @@ void __noreturn barebox_pbl_start(unsigned long membase, unsigned long memsize,
 	else if (IS_ENABLED(CONFIG_ARMV7R_MPU))
 		set_cr(get_cr() | CR_C);
 
-	pr_debug("uncompressing barebox binary at 0x%p (size 0x%08x) to 0x%08lx (uncompressed size: 0x%08x)\n",
+	pr_debug("uncompressing barebox ELF at 0x%p (size 0x%08x) to 0x%08lx (uncompressed size: 0x%08x)\n",
 			pg_start, pg_len, barebox_base, uncompressed_len);
 
 	pbl_barebox_uncompress((void*)barebox_base, pg_start, pg_len);
 
-	handoff_data_move(handoff_data);
+	pr_debug("relocating ELF in place\n");
 
-	sync_caches_for_execution();
+	struct elf_image elf;
+	int ret;
+
+	ret = elf_open_binary_into(&elf, (void *)barebox_base);
+	if (ret) {
+		pr_err("Failed to open ELF binary: %d\n", ret);
+		hang();
+	}
+
+	ret = elf_load_inplace(&elf);
+	if (ret) {
+		pr_err("Failed to relocate ELF: %d\n", ret);
+		hang();
+	}
+
+	pr_debug("ELF entry point: 0x%llx\n", elf.entry);
 
 	if (IS_ENABLED(CONFIG_THUMB2_BAREBOX))
-		barebox = (void *)(barebox_base + 1);
+		barebox = (void *)(unsigned long)(elf.entry | 1);
 	else
-		barebox = (void *)barebox_base;
+		barebox = (void *)(unsigned long)elf.entry;
+
+	handoff_data_move(handoff_data);
+
+	sync_caches_for_execution();
 
-	pr_debug("jumping to uncompressed image at 0x%p\n", barebox);
+	pr_debug("jumping to ELF entry point at 0x%p\n", barebox);
 
 	if (IS_ENABLED(CONFIG_CPU_V7) && boot_cpu_mode() == HYP_MODE)
 		armv7_switch_to_hyp();

-- 
2.47.3