altos/stm: Add comments to the .ld files explaining how the romconfig stuff works

[fw/altos] / src / stm / altos-loader.ld

diff --git a/src/stm/altos-loader.ld b/src/stm/altos-loader.ld
index 50a425c75309f2cf203bf25d200f50e2706cbcfe..14b45351d3ce8876fa2c96562df417af5cd8ed53 100644 (file)
--- a/src/stm/altos-loader.ld
+++ b/src/stm/altos-loader.ld
@@ -35,9 +35,18 @@ SECTIONS {
 
                . = ORIGIN(rom) + 0x100;
 
+               /* Ick. What I want is to specify the
+                * addresses of some global constants so
+                * that I can find them across versions
+                * of the application. I can't figure out
+                * how to make gnu ld do that, so instead
+                * we just load the two files that include
+                * these defines in the right order here and
+                * expect things to 'just work'. Don't change
+                * the contents of those files, ok?
+                */
                ao_romconfig.o(.romconfig*)
                ao_product.o(.romconfig*)
-
                *(.text)        /* Executable code */
                *(.rodata)      /* Constants */
 
@@ -48,9 +57,20 @@ SECTIONS {
        } > rom
        __text_end__ = .;
 
+       /* Boot data which must live at the start of ram so that
+        * the application and bootloader share the same addresses.
+        * This must be all uninitialized data
+        */
+       .boot (NOLOAD) : {
+               __boot_start__ = .;
+               *(.boot)
+               . = ALIGN(4);
+               __boot_end__ = .;
+       } >ram
+
        /* Functions placed in RAM (required for flashing) */
        .textram : {
-               __text_ram_start = .;
+               __text_ram_start__ = .;
                __data_start__ = .;
                *(.text.ram)
                . = ALIGN(4);