From 5ff4476ccb092eb85f79997933ea579d81a4704b Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Mon, 22 Mar 2021 23:58:03 -0500
Subject: [PATCH] Comment, clean up some PlatformIO scripts

---
 buildroot/share/PlatformIO/ldscripts/lerdge.ld     |  6 +++---
 buildroot/share/PlatformIO/scripts/openblt.py      |  7 ++++---
 .../share/PlatformIO/scripts/stm32_bootloader.py   | 14 +++++++++++++-
 .../PlatformIO/variants/MARLIN_F4x7Vx/ldscript.ld  |  6 +++---
 4 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/buildroot/share/PlatformIO/ldscripts/lerdge.ld b/buildroot/share/PlatformIO/ldscripts/lerdge.ld
index aa0b1dd9cb..f36ebcdea1 100644
--- a/buildroot/share/PlatformIO/ldscripts/lerdge.ld
+++ b/buildroot/share/PlatformIO/ldscripts/lerdge.ld
@@ -40,9 +40,9 @@ _Min_Stack_Size = 0x400;; /* required amount of stack */
 /* Specify the memory areas */
 MEMORY
 {
-FLASH (rx)      : ORIGIN = 0x8000000 + LD_FLASH_OFFSET, LENGTH = LD_MAX_SIZE - LD_FLASH_OFFSET
-RAM (xrw)      : ORIGIN = 0x20000000, LENGTH = LD_MAX_DATA_SIZE
-CCMRAM (rw)      : ORIGIN = 0x10000000, LENGTH = 64K
+FLASH (rx)  : ORIGIN = 0x08000000 + LD_FLASH_OFFSET, LENGTH = LD_MAX_SIZE - LD_FLASH_OFFSET
+RAM (xrw)   : ORIGIN = 0x20000000, LENGTH = LD_MAX_DATA_SIZE
+CCMRAM (rw) : ORIGIN = 0x10000000, LENGTH = 64K
 }
 
 /* Define output sections */
diff --git a/buildroot/share/PlatformIO/scripts/openblt.py b/buildroot/share/PlatformIO/scripts/openblt.py
index 2911a28e78..01cd9c9ef2 100644
--- a/buildroot/share/PlatformIO/scripts/openblt.py
+++ b/buildroot/share/PlatformIO/scripts/openblt.py
@@ -1,5 +1,6 @@
-# Generate the firmware as OpenBLT needs
-
+#
+# Convert the ELF to an SREC file suitable for some bootloaders
+#
 import os,sys
 from os.path import join
 
@@ -10,5 +11,5 @@ env.AddPostAction(
     env.VerboseAction(" ".join([
         "$OBJCOPY", "-O", "srec",
         "\"$BUILD_DIR/${PROGNAME}.elf\"", "\"$BUILD_DIR/${PROGNAME}.srec\""
-    ]), "Building " + join("$BUILD_DIR","${PROGNAME}.srec"))
+    ]), "Building " + join("$BUILD_DIR", "${PROGNAME}.srec"))
 )
diff --git a/buildroot/share/PlatformIO/scripts/stm32_bootloader.py b/buildroot/share/PlatformIO/scripts/stm32_bootloader.py
index bbec61750c..1ceff84b8f 100644
--- a/buildroot/share/PlatformIO/scripts/stm32_bootloader.py
+++ b/buildroot/share/PlatformIO/scripts/stm32_bootloader.py
@@ -7,18 +7,28 @@ Import("env")
 from SCons.Script import DefaultEnvironment
 board = DefaultEnvironment().BoardConfig()
 
+#
+# Copy the firmware.bin file to build.firmware, no encryption
+#
 def noencrypt(source, target, env):
   firmware = os.path.join(target[0].dir.path, board.get("build.firmware"))
   shutil.copy(target[0].path, firmware)
 
+#
+# For build.offset define LD_FLASH_OFFSET, used by ldscript.ld
+#
 if 'offset' in board.get("build").keys():
   LD_FLASH_OFFSET = board.get("build.offset")
 
+  # Remove an existing VECT_TAB_OFFSET from CPPDEFINES
   for define in env['CPPDEFINES']:
     if define[0] == "VECT_TAB_OFFSET":
       env['CPPDEFINES'].remove(define)
+
+  # Replace VECT_TAB_OFFSET with our LD_FLASH_OFFSET
   env['CPPDEFINES'].append(("VECT_TAB_OFFSET", LD_FLASH_OFFSET))
 
+  # Get upload.maximum_ram_size (defined by /buildroot/share/PlatformIO/boards/VARIOUS.json)
   maximum_ram_size = board.get("upload.maximum_ram_size")
 
   for i, flag in enumerate(env["LINKFLAGS"]):
@@ -27,7 +37,9 @@ if 'offset' in board.get("build").keys():
     if "-Wl,--defsym=LD_MAX_DATA_SIZE" in flag:
       env["LINKFLAGS"][i] = "-Wl,--defsym=LD_MAX_DATA_SIZE=" + str(maximum_ram_size - 40)
 
+#
+# Only copy the file if there's no encrypt
+#
 board_keys = board.get("build").keys()
-# Only copy file if there's no encryptation
 if 'firmware' in board_keys and not 'encrypt' in board_keys:
   env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", noencrypt)
diff --git a/buildroot/share/PlatformIO/variants/MARLIN_F4x7Vx/ldscript.ld b/buildroot/share/PlatformIO/variants/MARLIN_F4x7Vx/ldscript.ld
index 19eec62fba..aa685e8111 100644
--- a/buildroot/share/PlatformIO/variants/MARLIN_F4x7Vx/ldscript.ld
+++ b/buildroot/share/PlatformIO/variants/MARLIN_F4x7Vx/ldscript.ld
@@ -58,9 +58,9 @@ _Min_Stack_Size = 0x400; /* required amount of stack */
 /* Specify the memory areas */
 MEMORY
 {
-RAM (xrw)      : ORIGIN = 0x20000000, LENGTH = LD_MAX_DATA_SIZE
-CCMRAM (rw)      : ORIGIN = 0x10000000, LENGTH = 64K
-FLASH (rx)     : ORIGIN = 0x8000000 + LD_FLASH_OFFSET, LENGTH = LD_MAX_SIZE - LD_FLASH_OFFSET
+RAM (xrw)   : ORIGIN = 0x20000000, LENGTH = LD_MAX_DATA_SIZE
+CCMRAM (rw) : ORIGIN = 0x10000000, LENGTH = 64K
+FLASH (rx)  : ORIGIN = 0x08000000 + LD_FLASH_OFFSET, LENGTH = LD_MAX_SIZE - LD_FLASH_OFFSET
 }
 
 /* Define output sections */