binman: Record the parent section of each section

[oweals/u-boot.git] / tools / binman / etype / u_boot_spl_bss_pad.py

diff --git a/tools/binman/etype/u_boot_spl_bss_pad.py b/tools/binman/etype/u_boot_spl_bss_pad.py
index 65f631d3c5e4d6080ade38ec877252b161a12002..00b7ac50040ef752a11f9705bbc493690e167127 100644 (file)
--- a/tools/binman/etype/u_boot_spl_bss_pad.py
+++ b/tools/binman/etype/u_boot_spl_bss_pad.py
@@ -14,6 +14,22 @@ from blob import Entry_blob
 import tools
 
 class Entry_u_boot_spl_bss_pad(Entry_blob):
+    """U-Boot SPL binary padded with a BSS region
+
+    Properties / Entry arguments:
+        None
+
+    This is similar to u_boot_spl except that padding is added after the SPL
+    binary to cover the BSS (Block Started by Symbol) region. This region holds
+    the various used by SPL. It is set to 0 by SPL when it starts up. If you
+    want to append data to the SPL image (such as a device tree file), you must
+    pad out the BSS region to avoid the data overlapping with U-Boot variables.
+    This entry is useful in that case. It automatically pads out the entry size
+    to cover both the code, data and BSS.
+
+    The ELF file 'spl/u-boot-spl' must also be available for this to work, since
+    binman uses that to look up the BSS address.
+    """
     def __init__(self, section, etype, node):
         Entry_blob.__init__(self, section, etype, node)