[PATCH 3/4] bloblist: add support for CONFIG_BLOBLIST_PASSAGE

[Harrison Mutai <harrison.mutai@arm.com>]

When the configuration option CONFIG_BLOBLIST_PASSAGE is selected, the
bloblist present in the incoming standard passage is utilised in-place.
There is no need to specify the size of the bloblist as the system
automatically detects it using the header information.

Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
---
 common/Kconfig    |  8 +++++++-
 common/bloblist.c | 18 ++++++++++--------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/common/Kconfig b/common/Kconfig
index f9489872fd..7b2db46ef0 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -1066,6 +1066,12 @@ config BLOBLIST_ALLOC
 	  specify a fixed address on systems where this is unknown or can
 	  change at runtime.
 
+config BLOBLIST_PASSAGE
+	bool "Use bloblist in-place"
+	help
+	  Use a bloblist in the incoming standard passage. The size is detected
+	  automatically so CONFIG_BLOBLIST_SIZE can be 0.
+
 endchoice
 
 config BLOBLIST_ADDR
@@ -1080,6 +1086,7 @@ config BLOBLIST_ADDR
 
 config BLOBLIST_SIZE
 	hex "Size of bloblist"
+	default 0x0 if BLOBLIST_PASSAGE
 	default 0x400
 	help
 	  Sets the size of the bloblist in bytes. This must include all
@@ -1090,7 +1097,6 @@ config BLOBLIST_SIZE
 config BLOBLIST_SIZE_RELOC
 	hex "Size of bloblist after relocation"
 	default BLOBLIST_SIZE if BLOBLIST_FIXED || BLOBLIST_ALLOC
-	default 0x0 if BLOBLIST_PASSAGE
 	default 0x20000 if (ARM && EFI_LOADER && GENERATE_ACPI_TABLE)
 	help
 	  Sets the size of the bloblist in bytes after relocation. Since U-Boot
diff --git a/common/bloblist.c b/common/bloblist.c
index 110bb9dc44..1fcd387593 100644
--- a/common/bloblist.c
+++ b/common/bloblist.c
@@ -475,6 +475,9 @@ int bloblist_reloc(void *to, uint to_size)
 {
 	struct bloblist_hdr *hdr;
 
+	if (!to_size)
+		return 0;
+
 	if (to_size < gd->bloblist->total_size)
 		return -ENOSPC;
 
@@ -505,13 +508,6 @@ int bloblist_init(void)
 	 * at a fixed address.
 	 */
 	bool from_addr = fixed && !xpl_is_first_phase();
-	/*
-	 * If U-Boot is in the first phase that an arch custom routine should
-	 * install the bloblist passed from previous loader to this fixed
-	 * address.
-	 */
-	bool from_boot_arg = fixed && xpl_is_first_phase();
-
 	if (xpl_prev_phase() == PHASE_TPL && !IS_ENABLED(CONFIG_TPL_BLOBLIST))
 		from_addr = false;
 	if (fixed)
@@ -519,7 +515,13 @@ int bloblist_init(void)
 				      CONFIG_BLOBLIST_ADDR);
 	size = CONFIG_BLOBLIST_SIZE;
 
-	if (from_boot_arg)
+
+	/*
+	 * If the current boot stage is the first phase of U-Boot, then an
+	 * architecture-specific routine should be used to handle the bloblist
+	 * passed from the previous boot loader
+	 */
+	if (xpl_is_first_phase() && !IS_ENABLED(CONFIG_BLOBLIST_ALLOC))
 		ret = xferlist_from_boot_arg(addr, size);
 	else if (from_addr)
 		ret = bloblist_check(addr, size);
-- 
2.46.2