[PATCHv8 3/3] memory: reserve from start_addr_sp to initial_relocaddr

rs at ti.com rs at ti.com
Wed May 13 22:49:43 CEST 2026


From: Randolph Sapp <rs at ti.com>

Add a new global data struct member called initial_relocaddr. This
stores the original value of relocaddr, directly from setup_dest_addr.
This is specifically to avoid any adjustments made by other init
functions.

Reserve the memory from gd->start_addr_sp - CONFIG_STACK_SIZE to
gd->initial_relocaddr instead of gd->ram_top. This allows platform
specific relocation addresses to work without unnecessarily painting
over a large range.

Signed-off-by: Randolph Sapp <rs at ti.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---

v7:
	- Reinstate bank hopping logic for U-Boot reserved region
	- Update description for gd->initial_relocaddr, make it clear this is
	  also an exclusive value
	- Leave the PRAM region out of the reservation. Previous commit messages
	  indicate that this is intended.
v8:
	- Adjust initial_relocaddr doc string

 common/board_f.c                  | 9 ++++++++-
 include/asm-generic/global_data.h | 9 +++++++++
 lib/efi_loader/efi_memory.c       | 2 +-
 lib/lmb.c                         | 7 ++++---
 4 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/common/board_f.c b/common/board_f.c
index ce87c619e68..aeb53b4c274 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -330,6 +330,8 @@ __weak int arch_setup_dest_addr(void)
 
 static int setup_dest_addr(void)
 {
+	int ret;
+
 	debug("Monitor len: %08x\n", gd->mon_len);
 	/*
 	 * Ram is setup, size stored in gd !!
@@ -356,7 +358,12 @@ static int setup_dest_addr(void)
 	gd->relocaddr = gd->ram_top;
 	debug("Ram top: %08llX\n", (unsigned long long)gd->ram_top);
 
-	return arch_setup_dest_addr();
+	ret = arch_setup_dest_addr();
+	if (ret)
+		return ret;
+
+	gd->initial_relocaddr = gd->relocaddr;
+	return 0;
 }
 
 #ifdef CFG_PRAM
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 745d2c3a966..8d1d49b1133 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -107,6 +107,15 @@ struct global_data {
 	 * GDB using the 'add-symbol-file u-boot <relocaddr>' command.
 	 */
 	unsigned long relocaddr;
+	/**
+	 * @initial_relocaddr: top address of U-Boot in RAM
+	 *
+	 * This should be the value of relocaddr after setup_dest_addr() and
+	 * before reserve_pram() or any other allocations or reservations shift
+	 * it. This address will, depending on the platform, be equivalent to
+	 * ram_top and should also be considered an exclusive address.
+	 */
+	unsigned long initial_relocaddr;
 	/**
 	 * @irq_sp: IRQ stack pointer
 	 */
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index 046a2bb4641..9d7eda9422f 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -869,7 +869,7 @@ static void add_u_boot_and_runtime(void)
 	/* Add U-Boot */
 	uboot_start = ((uintptr_t)map_sysmem(gd->start_addr_sp, 0) -
 		       uboot_stack_size) & ~EFI_PAGE_MASK;
-	uboot_pages = ((uintptr_t)map_sysmem(gd->ram_top - 1, 0) -
+	uboot_pages = ((uintptr_t)map_sysmem(gd->initial_relocaddr - 1, 0) -
 		       uboot_start + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 	efi_update_memory_map(uboot_start, uboot_pages, EFI_BOOT_SERVICES_CODE,
 			      false, false);
diff --git a/lib/lmb.c b/lib/lmb.c
index 8f12c6ad8e5..27c8565e590 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -540,13 +540,14 @@ static void lmb_reserve_uboot_region(void)
 	ulong pram = 0;
 
 	rsv_start = gd->start_addr_sp - CONFIG_STACK_SIZE;
-	end = gd->ram_top;
+	end = gd->initial_relocaddr;
 
 	/*
 	 * Reserve memory from aligned address below the bottom of U-Boot stack
-	 * until end of RAM area to prevent LMB from overwriting that memory.
+	 * until the original relocation address to prevent LMB from
+	 * overwriting that memory.
 	 */
-	debug("## Current stack ends at 0x%08lx ", (ulong)rsv_start);
+	debug("## Current stack ends at 0x%08lx\n", (ulong)rsv_start);
 
 #ifdef CFG_PRAM
 	pram = env_get_ulong("pram", 10, CFG_PRAM);
-- 
2.54.0



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