Use the _mt_tss label and the placement new operator to create the
Tss class instance in the mtc region. Update the hard-coded
TSS base address to use the virtual mtc address.
On exception, the CPU first checks the IDT in order to find the
associated ISR. The IDT must therefore be placed in the mode transition
pages to make them available for non-core threads.
The limit is set to match the TSS size - 1 and the base address is
hardcoded to the *current* address of the TSS instance (0x3a1100).
TODO: Set the base address using the 'tss' label. If the TSS descriptor
format were not so utterly unusable this would be straightforward.
Changes to the code that indirectly lead to a different location
of the tss result in #GP since the base address will be invalid.
The class Genode::Tss represents a 64-bit Task State Segment (TSS) as
specified by Intel SDM Vol. 3A, section 7.7.
The setup function sets the stack pointers for privilege levels 0-2 to
the kernel stack address. The load function loads the TSS segment
selector into the task register.
Implement user argument setter and getter support functions. The mapping of
the state registers corresponds to the system call parameter passing
convention.
The instruction pointer is the first field of the master context and can
directly be used as a jump argument, which avoids additional register
copy operations.
Point stack to client context region and save registers using push
instructions.
Note that since the push instruction first increments the stack pointer
and then stores the value on the stack, the RSP has to point one field
past RBP before pushing the first register value.
As the kernel entry is called from the interrupt handler the stack
layout is as specified by Intel SDM Vol. 3A, figure 6-8. An additional
vector number is stored at the top of the stack.
Gather the necessary client information from the interrupt stack frame
and store it in the client context.
The new errcode field is used to store the error code that some
interrupts provide (e.g. #PF). Rework mode transition reserved space and
offset constants to match the new CPU_state layout.
The macros are used to assign syscall arguments to specific registers.
Using the AMD64 parameter passing convention avoids additional copying of
variables since the C++ function parameters are already in the right
registers.
The interrupt return instruction in IA-32e mode applies the prepared
interrupt stack frame to set the RFLAGS, CS and SS segment as well as
the RIP and RSP registers. It then continues execution of the user code.
For detailed information refer to Intel SDM Vol. 3A, section 6.14.3.
After activating the client page tables the client context cannot be
accessed any longer. The mode transition buffer however is globally
mapped and can be used to restore the remaining register values.
Set the stack pointer to the R8 field in the client context to enable
restoring registers by popping values of the stack.
After this step the only remaining registers that do not contain client
values are RAX, RSP and RIP.
Note that the client value of RAX is pop'd to the global buffer region as
the register will still be used by subsequent steps. It will be restored to
the value in the buffer area just prior to resuming client code execution.
Set I/O privilege level to 3 to allow core to perform port I/O from
userspace. Also make sure the IF flag is cleared for now until interrupt
handling is implemented.
Setup an IA-32e interrupt stack frame in the mode transition buffer region.
It will be used to perform the mode switch to userspace using the iret
instruction.
For detailed information about the IA-32e interrupt stack frame refer to
Intel SDM Vol. 3A, figure 6-8.
The constants specify offset values of CPU context member variables as
specified by Genode::Cpu_state [1] and Genode::Cpu::Context [2].
[1] - repos/base/include/x86_64/cpu/cpu_state.h
[2] - repos/base-hw/src/core/include/spec/x86/cpu.h
The new entries specify a 64-bit code segment with DPL 3 at index 3 and a
64-bit data segment with DPL 3 at index 4.
These segments are needed for transitioning to user mode.
A pointer to the client context is placed in the mt_client_context_ptr area.
It is used to pass the current client context to the lowlevel mode-switching
assembly code.
IA-32e paging translates 48-bit linear addresses to 52-bit physical
addresses. Translation structures are hierarchical and four levels deep.
The current implementation supports regular 4KB and 1 GB and 2 MB large
page mappings.
Memory typing is not yet implemented since the encoded type bits depend
on the active page attribute table (PAT)*.
For detailed information refer to Intel SDM Vol. 3A, section 4.5.
* The default PAT after power up does not allow the encoding of the
write-combining memory type, see Intel SDM Vol. 3A, section 11.12.4.
* Add common IA-32e paging descriptor type:
The type represents a table entry and encompasses all fields shared by
paging structure entries of all four levels (PML4, PDPT, PD and PT).
* Simplify PT entry type by using common descriptor:
Differing fields are the physical address, the global flag and the memory
type flags.
* Simplify directory entry type by using common descriptor:
Page directory entries (PDPT and PD) have an additional 'page size' field
that specifies if the entry references a next level paging structure or
represents a large page mapping.
* Simplify PML4 entry type by using common descriptor
Top-level paging structure entries (PML4) do not have a 'pat' flag and the
memory type is specified by the 'pwt' and 'pcd' fields only.
* Implement access right merging for directory paging entries
The access rights for translations are determined by the U/S, R/W and XD
flags. Paging structure entries that reference other tables must provide
the superset of rights required for all entries of the referenced table.
Thus merge access rights of new mappings into existing directory entries to
grant additional rights if needed.
* Add cr3 register definition:
The control register 3 is used to set the current page-directory base
register.
* Add cr3 variable to x86_64 Cpu Context
The variable designates the address of the top-level paging structure.
* Return current cr3 value as translation table base
* Set context cr3 value on translation table assignment
* Implement switch to virtual mode in kernel
Activate translation table in init_virt_kernel function by updating the
cr3 register.
* Ignore accessed and dirty flags when comparing existing table entries
These flags can be set by the MMU and must be disregarded.
* Add isr.s assembler file:
The file declares an array of Interrupt Service Routines (ISR) to handle
the exception vectors from 0 to 19, see Intel SDM Vol. 3A, section
6.3.1.
* Add Idt class:
* The class Genode::Idt represents an Interrupt Descriptor Table as
specified by Intel SDM Vol. 3A, section 6.10.
* The setup function initializes the IDT with 20 entries using the ISR
array defined in the isr.s assembly file.
* Setup and load IDT in Genode::Cpu ctor:
The Idt::setup function is only executed once on the BSP.
* Declare ISRs for interrupts 20-255
* Set IDT size to 256
This patch contains the initial code needed to build and bootstrap the
base-hw kernel on x86 64-bit platforms. It gets stuck earlier
because the binary contains 64-bit instructions, but it is started in
32-bit mode. The initial setup of page tables and switch to long mode is
still missing from the crt0 code.
A Nic::Session client can install a signal handler that is used to
propagate changes of the link-state by calling 'link_state_sigh()'.
The actual link state is queried via 'link_state()'.
The nic-driver interface now provides a Driver_notification callback,
which is used to forward link-state changes from the driver to the
Nic::Session_component.
The following drivers now provide real link state: dde_ipxe, nic_bridge,
and usb_drv. Currently, OpenVPN, Linux nic_drv, and lan9118 do not
support link state and always report link up.
Fixes#1327
If a client acknowledges the same packet more than once, the packet also
gets freed more than once. At the second attempt the underlaying
Bit_array will throw an 'Invalid_clear' exception, which results in an
uncaught exception that leads to an abort() call in the freeing
component.
Fixes#1462.
To ease debugging without the need to tweak the kernel every time, and to
support userland developers with useful information this commit extends several
warnings and errors printed by the kernel/core by which thread/application
caused the problem, and what exactly failed.
Fix#1382Fix#1406
The driver for the Freescale eSDHCv2 doesn't support the highest
available bus frequency by now and also the bus width may be set to a
higher value but that needs further checks on the capabilities of the
inserted card.
The commits provide a benchmark as it exists for the OMAP4 SDHC driver.
Fix#1458
The 'continue_hw_accelerated' assertion at the end of the recall handler
can fail in situations which are not problematic, for example if the
'Timer' thread has set the 'VMCPU_FF_TIMER' flag in the meantime and
requested a recall afterwards. Since we don't know for sure if a recall is
requested for the other flags as well, the assertion gets replaced by a
debug message, which gets printed if any of the 'not yet verified as safe'
flags is set.
Fixes#1426
The GUID partition table (GPT) is primarily used by systems using
(U)EFI and is a replacement for the legacy MBR. For now, the current
implementation is able to address up to 128 GUID partition entries
(GPE).
To enable the GPT support in 'part_blk' it has to be configured
accrodingly:
! <start name="part_blk">
! [...]
! <config use_gpt="yes">
! [...]
! </start>
If 'part_blk' is not able to find a valid GPT header it falls back
to using the MBR.
Current limitations:
Since no endian conversion takes place it only works on LE platforms
and of all characters in the UTF-16 encoded name field of an entry
only the ones included in the ASCII encoding are printed. It also
ignores all GPE attributes.
Issue #1429.
The hover reports provides information about the session currently
pointed-to, i.e., hovered session. It can be enabled by the 'hover'
attribute of nitpicker's 'report' configuration element
<report hover="yes" />
Fixes#1442
The bindings for 32bit did not consider that in the syscall_3 function
edx changes due to the assembly instructions and that in the syscall_4
function edx and ecx change. So, the compiler wrongly assumed that the
content of these registers stayed unchanged.
Fixes#1447
In the past, unmap sometimes occured on RM clients that have no thread,
PD, or translation table assigned. However, this shouldn't be the
case anymore.
Fixes#504
* Introduce hw-specific crt0 for core that calls e.g.: init_main_thread
* re-map core's main thread UTCB to fit the right context area location
* switch core's main thread's stack to fit the right context area location
Fix#1440
