This change allows us to know, from just the kernel and dtb, where user
level untyped objects start being allocated from.
- allocate rootserver objects from last available freemem region.
- move create_rootserver_objects call into init_freemem.
Previously, the boot allocator would do dynamic calculations to
minimise fragmentation, then throw away the smallest regions.
With the new boot allocator, we can reasonably predict that
fragmentation will create at most one extra region, so this commit
adds one freemem slot for ARM.
Prior to this change, the boot process would dynamically allocate
memory for root server objects based on the order of initialisation.
Allocation was a best-fit algorithm.
This change preallocates all memory for root server objects to an
aligned untyped just after the user image. By allocating the objects in
order of size, allocation is greatly simplified and the ability to
reproduce the allocation offline based on the kernel and user image
sizes is increased.
init_freemem sets up available regions of memory for the hardware that
seL4 is booting on. Previously this function was duplicated across
architectures, with minor duplication.
This change provides a top-level init_freemem suitable for all
architectures.
- arm/riscv: change get_avail_p_reg to return whole p_reg array
- update all architectures to use new init_freemem.
- wrap init_freemem calls with arch_init_freemem for each arch, where
arch_init_freemem sets up the available and reserved regions of memory
which are passed to init_freemem.
The memory used for the irq cnode is never available to the user. As a
result this memory can be allocated statically, simplifying the
bootcode.
- remove allocation of irq cnode
- add static init
- generate irq cnode size from cmake for arm
- add static constants for riscv, x86 as there is no variability at the
moment.
2 freemem regions is far to prohibitive on platforms that have fragmented initial
memory. Ultimately ARM should be changed to also have more than 2, but is being
deferred for now as it will result in trivial verification breakage.
On 64-bit platforms physical address could be >2^32 offset from a virtual address. This
changes offsets to match the word size of the target architecture
Kernel objects cannot be created from device untypeds, with the
exception of frames, which do not get zeroed and cannot be used
as an IPC buffer. Device untypeds additionally cannot be used
in the construction of ASID pools.
This then changes the API to the rootserver (i.e. bootinfo) to
send device untypeds instead of device frames. On ARM these
device untypeds are the same as the previously exported device
frame regions. On x86 PCI scanning is removed and all physical
memory addresses (that are not important for kernel integrity)
are released to the user.
In order to have bits in the frame and untyped caps on ARM the
number of software ASIDs had to be reduced from 2^18 to 2^17,
and the maximum untyped size reduced from 2^31 to 2^30
If the multiboot memory list exists, then it may contain more
than just the single contiguous memory region listed in 'mem_upper'
Therefore we use it to populate a more complete free memory list,
if it exists
