The leading - makes it rather inconsistent with the majority of other
projects around the world. Use the form everyone else uses.
To solve this, properly pass prefix to inner makes as was always
intended.
Fixes: https://github.com/libopencm3/libopencm3/issues/1058
Renamed every instance of variable CFLAGS in target specific Makefiles
to TGT_CFLAGS to free up CFLAGS for user defined compiler flags.
Added information in README.md about existence and usage of CFLAGS
environment variable in build process.
-ggdb3 make slightly bigger .elf files, but allows gdb to understand
macros, which libopenocm3 uses somewhat extensively. Make this the
default, and pull it up to the common base makefile, so it can be easily
substituted.
Add I/O mux controller which is required to mux pins according to
their used function. For all pads, the alternative function 0 is
GPIO. For different pin mux function refer to the reference manual.
This adds GPIO module support. GPIO can be controlled using the GPIO
number as stated in the reference manual, similar to Linux. Also
32-bit access to whole ports is possible. Reading a GPIO is possible
without muxing the pad as GPIO, however writing a GPIO needs the pad
to be muxed as GPIO.
This adds UART support for Vybrid VF6xx. Baud rate is calculated
from IPG clock, which need to be initialized by using the
ccm_calculate_clocks functions. Also clock need to be gated using
the ccm_clock_gate_enable function. Tested with an unitialized
UART with a baud rate of 115200.
Extend the clock controller module with a function to calculate
core clocks from the current registers settings. On Vybrid, we
assume that the core clocks are setup by the main operating system
running on the Cortex-A5. Nevertheless we need to know their actual
values in order to calculate other clocks or baud rates.
Verified on a Colibri VF61, which calculates following values:
ccm_core_clk: 500210526
ccm_platform_bus_clk: 166736842
ccm_ipg_bus_clk: 83368421
Add initial memorymap for Vybrid VF6xx module. Also add the clock
control module which allows to control system clocks and enable
clocks of individual pheripherials.
Set Vector Table Offset to memory location of our vector table.
Since we put the whole programm including the vector table into
memory, we need to make use of the Cortex-M4 system control block
Vector Table Offset Register (VTOR).
Freescale Vybrid is a familiy of ARM SoC, wheras the VF6xx models
have two cores in one SoC, a Cortex-A5 and a Cortex-M4. This adds
initial support for the Cortex-M4 in the libopencm3 library.
By using two different ram areas (pc_ram and ps_ram) the user can
put the code in a RAM area bounded to the code bus. The data can
be stored in the data area. However, currently the initial values
of for the variables in the data section are stored in the code
section and copied to the ram section by the initialization code
(like it's copied from ROM to RAM on microcontrollers).
Karl Palsson