Files
bsb2/kernel/thread/thread.cc
2026-02-24 10:50:12 +01:00

111 lines
3.3 KiB
C++

// vim: set noet ts=4 sw=4:
#include "thread.h"
#include "../arch/core_ring.h"
#include "../memory/pageframealloc.h"
#include "../memory/pagetable.h"
#include "../debug/kernelpanic.h"
#include "../interrupt/guard.h"
#include "debug/output.h"
static int idCounter = 1; // counter for task IDs
//extern four_lvl_paging_t paging_tree;
extern pagetable_t identity_table;
void Thread::kickoff(uintptr_t param1, uintptr_t param2, uintptr_t param3) {
Thread *thread = reinterpret_cast<Thread *>(param1);
assert(thread != nullptr && "Kickoff got nullptr pointer to Thread");
(void)param2; // will be used later
(void)param3; // will be used later
// The core must have entered level 1/2 to cause a thread to be scheduled.
Guard::leave();
if(!thread->isKernel)
Core::Ring::switchToUsermode(thread->StackPointer.user, (void*)0x4000000, 0);
else
if(thread->start == nullptr)
thread->action();
else
((void(*)())thread->start)();
}
void Thread::load_paging(Thread* t){
load_cr3((void*)(t->paging_tree->l4));
}
Thread::Thread (bool kernel, void * startframe, int num_pages): queue_link(nullptr), isKernel(kernel), start(startframe), id(idCounter++), kill_flag(false){
StackPointer.isr = reinterpret_cast<void *>((uintptr_t)PageFrameAllocator::alloc(true)+STACK_SIZE);//(reserved_stack_space_isr + STACK_SIZE);
StackPointer.user = (void*)(0x61FF000+STACK_SIZE);
paging_tree = (four_lvl_paging_t*)PageFrameAllocator::alloc(true);
memset(paging_tree, 0, 4096);
create_basic_page_table(paging_tree, &identity_table);
appcode_table = (pagetable_t*) PageFrameAllocator::alloc(true);
memset(appcode_table, 0, 4096);
appstack_table = (pagetable_t*) PageFrameAllocator::alloc(true);
memset(appstack_table, 0, 4096);
assert(num_pages < 512); //limit for application code size is 2M
for(uint8_t i=0; i<num_pages; i++){
appcode_table->entries[i] = {
.present = 1,
.user = 1,
.address = ((uintptr_t)startframe >> 12) + i
};
}
// insert app code pages at 32*512*4096 = 0x4000000
paging_tree->l2->entries[32] = {
.present = 1,
.write = 1,
.user = 1,
.address = (uintptr_t)(appcode_table) >> 12
};
uintptr_t user_stackframe_p = ((uintptr_t)PageFrameAllocator::alloc(false));
appstack_table->entries[511] = {
.present = 1,
.write = 1,
.user = 1,
.address = user_stackframe_p >> 12
};
// insert stack page at 48*512*4096 = 0x6000000
paging_tree->l2->entries[48] = {
.present = 1,
.write = 1,
.user = 1,
.address = (uintptr_t)(appstack_table) >> 12
};
prepareContext(StackPointer.isr, context, kickoff, reinterpret_cast<uintptr_t>(this), 0, 0);
}
Thread::Thread() : Thread(false, 0) {}
//Thread::Thread() : queue_link(nullptr), id(idCounter++), kill_flag(false) {
// void *tos = reinterpret_cast<void *>(reserved_stack_space_isr + STACK_SIZE);
// prepareContext(tos, context, kickoff, reinterpret_cast<uintptr_t>(this), 0, 0);
//}
void Thread::resume(Thread *next) {
load_paging(next);
context_switch(&next->context, &context);
}
void* Thread::operator new(size_t sz) noexcept
{
if (sz == 0)
++sz; // avoid std::malloc(0) which may return nullptr on success
void *ptr = PageFrameAllocator::alloc(true);
return ptr;
}
void Thread::go() {
load_paging(this);
context_launch(&context);
}
void Thread::action() { kernelpanic("Wrong entry / missing action in Thread"); }