This patch slightly revises CFLAGS and LDFLAGS to specify the
optimization and debugging options and linker script in a way that is
compatible with using Clang as the C compiler and to invoke the linker
(i.e. CC = clang and LD = clang).
This patch adds a driver for an MMIO-accessible 16X50 UART. It
assumes that the boot firmware assigned an MMIO range to the UART. It
operates in polled mode with FIFOs enabled.
This patch adds the pci.c and pci.h files, which support access to PCI
configuration registers through a function interface. It defines the
PCI configuration register access I/O port addresses and the
pci_config_addr union and structure to assist in specifying addresses
of PCI configuration registers. It also defines the PCI configuration
register identifier for PCI BAR0.
This patch also adds wrappers for 32-bit 'in' and 'out' port I/O
instructions. They were placed in helpers.S, since they may be useful
to other modules besides just the PCI support module.
This patch moves the compiler and linking options related to QuarkX1000
SoC to Makefile.x86_quarkX1000 since it is more suitable. For instance,
'-m32' should be used in any platform based on QuarkX1000, not only
Galileo. The same rationale applies for the others options (e.g. -march,
mtune).
According to [1], we should disable non-maskable and maskable interrupts
while initializing RTC. Otherwise, the RTC may be left in an undefined
state (non-functional) if an interrupt occurs. Currently, maskable
interrupts are already disabled, but NMI is not.
This patch adds helpers APIs to enable/disable non-maskable interrupts
(NMI) and changes rtc_init() to disable NMI while initializing the RTC.
NMI enable/disable code is legacy-PC specific therefore it was put in
driver/legacy_pc/ directory.
Regarding the RTC initialization changes, just calling nmi_disable() and
nmi_enable is not enough since NMI and RTC share the same IO port. So We
should also set the NMI_ENABLE bit while selecting the RTC_INDEX.
Additionally, the nmi_disable() call is not strictly required since we
set the NMI_ENABLE bit while selecting the RTC_INDEX. However, to make
clear hat we are disabling NMI and to improve readability (by matching
NMI disable/enable), the nmi_disable() call was purposely used.
[1] http://wiki.osdev.org/RTC
This is a refactoring patch, no functionality is changed. It moves
loader.S and galileo.ld from platform/galileo/ to cpu/x86/ directory
since they seem to be more SoC-specific than platform-specific.
It also renames galileo.ld to quarkX1000.ld since it can be used by
any platform based on Quark X1000 SoC, not only Galileo.
Furthermore, this patch also renames loader.S to bootstrap_quarkX1000.S
since it is pretty much a bootstrap code to any platform based on Quark
X1000 SoC.
This commit turns cpu_init() into a SoC-agnostic function by
removing any SoC specific calls and isolating them into their
own SoC implementation.
We start this by isolating all IRQs initialization code from
the legacy-pc target, pic_init() and spurious IRQ7 registration,
into a new interface: irq_init() from irq.h. Future SoCs will have
to provide their own implementation of this interface.
This model is to be followed by future initialization code that
we may need to add and which is not common to all x86 SoCs.
Now the cpu/x86/ provides a Makefile.x86_common and a
Makefile.x86_pc. The former includes the common Makefile
and adds legacy pc specific implementations (currently,
drivers only) into the building context, while the latter
has everything that defines the bootstrap of a x86 CPU.
This commit also fixes platform/galileo/ so it includes the
correct makefile - Makefile.x86_quarkX1000. Galileo uses
a Quark X1000 SoC which is not an IBM Generic PC-like CPU,
but it does provide most of a PCs peripherals through
its "Legacy Bridge". Thus, it makes sense that QuarkX1000's
Makefile includes code from the legacy_pc x86 cpu.
