x1000: bootloader: add mainline Linux boot option

This adds a *very basic* Linux loader to the Rockbox bootloader,
which allows running a mainline Linux kernel using the following
file layout on the SD card:

- /uImage
- /linux_cmdline.txt

The command line arguments are listed in linux_cmdline.txt, all
lines are concatenated together and whitespace is converted into
spaces. Comments aren't supported however.

The loader doesn't support the modern devicetree boot protocol,
so it can only pass command line arguments. It would be easy to
support an appended dtb though.

Change-Id: I373f465dbbdafe94738f619748cbb0278fc2c25f

1 files changed, 1 insertions, 0 deletions

diff --git a/bootloader/x1000/x1000bootloader.h b/bootloader/x1000/x1000bootloader.h
index 88d4e3585b..587a820eaf 100644
--- a/bootloader/x1000/x1000bootloader.h
+++ b/bootloader/x1000/x1000bootloader.h
@@ -141,6 +141,7 @@ void bootloader_restore(void);
 void boot_rockbox(void);
 void boot_of_player(void);
 void boot_of_recovery(void);
+void boot_linux(void);
 void shutdown(void);
 void reboot(void);