Example Applications
The boot_demo2 application can be used along with this application to easily demonstrate that the
boot loader is actually updating the on-chip flash.
Note that the LM4F232 and other Blizzard-class devices also support the serial and USB boot
loaders in ROM. To make use of this function, link your application to run at address 0x0000 in flash
and enter the bootloader using the ROM_UpdateSerial and ROM_UpdateUSB functions (defined
in rom.h). This mechanism is used in the utils/swupdate.c module when built specifically targeting
a suitable Blizzard-class device.
2.4
Boot Loader Demo 2 (boot_demo2)
An example to demonstrate the use of a flash-based boot loader. At startup, the application will
configure the UART, USB and Ethernet peripherals, wait for a widget on the screen to be pressed,
and then branch to the boot loader to await the start of an update. If using the serial boot loader
(boot_serial), the UART will always be configured at 115,200 baud and does not require the use of
auto-bauding.
This application is intended for use with any of the three flash-based boot loader flavors (boot_eth,
boot_serial or boot_usb) included in the software release. To accommodate the largest of these
(boot_usb), the link address is set to 0x2800. If you are using serial or Ethernet boot loader, you
may change this address to a 1KB boundary higher than the last address occupied by the boot
loader binary as long as you also rebuild the boot loader itself after modifying its bl_config.h file to
set APP_START_ADDRESS to the same value.
The boot_demo1 application can be used along with this application to easily demonstrate that the
boot loader is actually updating the on-chip flash.
Note that the LM4F232 and other Blizzard-class devices also the support serial and USB boot
loaders in ROM. To make use of this function, link your application to run at address 0x0000 in
flash and enter the bootloader using either the ROM_UpdateUSB or ROM_UpdateSerial functions
(defined in rom.h). This mechanism is used in the utils/swupdate.c module when built specifically
targeting a suitable Blizzard-class device.
2.5
Boot Loader (boot_serial)
The boot loader is a small piece of code that can be programmed at the beginning of flash to act as
an application loader as well as an update mechanism for an application running on a Tiva C Series
microcontroller, utilizing either UART0, I2C0, SSI0, or USB. The capabilities of the boot loader are
configured via the bl_config.h include file. For this example, the boot loader uses UART0 to load an
application.
The configuration is set to boot applications which are linked to run from address 0x2800 in flash.
This is higher than strictly necessary but is intended to allow the example boot loader-aware appli-
cations provided in the release to be used with any of the three boot loader example configurations
supplied (serial or USB) without having to adjust their link addresses.
Note that the LM4F232 and other Blizzard-class devices also support serial boot loaders in ROM.
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February 22, 2017