some header improvements

update README

update README

update README

also clean tests and benchmarks on clean_all

document __prepare_exec

make it more obvious dynamic elf isn't supported

update elf docs

check effective id of create

check spawn exhaustion

add spawn benchmark

intial working sys_spawn

initial exec support

use correct sfence.vma

simplify enter_rpc, remove finalize_rpc

calculate rpc stack top slightly differently

mark some hot path functions inline

move stack modifications to be earlier in rpc

speed up creating threads quite a bit

speed up creating threads quite a bit

speed up creating threads quite a bit

test all ipc variants more-or-less properly

smp on visionfive2 'works'

remember to set regs to some valid address

rpc actually marks and unmarks stack regions

clarify visionfive2 docs

bookkeeping