Files
lk/arch/x86/arch.c
Travis Geiselbrecht 5a520eca3e [arch][x86] start getting inter-processor-interrupts working
-Move the local apic driver to arch/x86
-Add routines to send IPIs between cpus

Something is unstable at the moment and the system crashes after a while
with random corruptions when using SMP.
2025-04-01 00:40:50 -07:00

154 lines
4.0 KiB
C

/*
* Copyright (c) 2009 Corey Tabaka
* Copyright (c) 2015 Intel Corporation
*
* Use of this source code is governed by a MIT-style
* license that can be found in the LICENSE file or at
* https://opensource.org/licenses/MIT
*/
#include <lk/debug.h>
#include <arch.h>
#include <arch/ops.h>
#include <arch/x86.h>
#include <arch/x86/mmu.h>
#include <arch/x86/descriptor.h>
#include <arch/x86/feature.h>
#include <arch/fpu.h>
#include <arch/mmu.h>
#include <kernel/vm.h>
#include <platform.h>
#include <sys/types.h>
/* Describe how start.S sets up the MMU.
* These data structures are later used by vm routines to lookup pointers
* to physical pages based on physical addresses.
*/
struct mmu_initial_mapping mmu_initial_mappings[] = {
/* 64GB of the first 64GB of memory mapped 1:1 */
{
.phys = MEMBASE,
.virt = KERNEL_ASPACE_BASE,
.size = PHYSMAP_SIZE, /* x86-64 maps first 64GB by default, 1GB on x86-32, 16MB in legacy mode */
.flags = 0,
.name = "physmap"
},
#if ARCH_X86_64
/* Another linear map of the first GB of memory where the kernel image
* lives at the top of the address space. */
{
.phys = MEMBASE,
.virt = KERNEL_BASE,
.size = 1*GB,
.flags = 0,
.name = "kernel"
},
#endif
/* null entry to terminate the list */
{ 0 }
};
/* early stack */
uint8_t _kstack[PAGE_SIZE] __ALIGNED(sizeof(unsigned long));
/* save a pointer to the multiboot information coming in from whoever called us */
/* make sure it lives in .data to avoid it being wiped out by bss clearing */
__SECTION(".data") uint32_t _multiboot_info;
/* main tss */
static tss_t system_tss __ALIGNED(16);
void x86_early_init_percpu(void) {
// enable caches
clear_in_cr0(X86_CR0_NW | X86_CR0_CD);
// configure the system TSS
// XXX move to a per cpu TSS in the percpu structure
#if ARCH_X86_32
system_tss.esp0 = 0;
system_tss.ss0 = DATA_SELECTOR;
system_tss.ss1 = 0;
system_tss.ss2 = 0;
system_tss.eflags = 0x00003002;
system_tss.bitmap = offsetof(tss_32_t, tss_bitmap);
system_tss.trace = 1; // trap on hardware task switch
#elif ARCH_X86_64
/* nothing to be done here, a fully zeroed TSS is a good starting point */
#endif
const uint selector = TSS_SELECTOR_BASE + 8 * arch_curr_cpu_num();
x86_set_gdt_descriptor(selector, &system_tss, sizeof(system_tss), 1, 0, 0, SEG_TYPE_TSS, 0, 0);
x86_ltr(selector);
/* load the kernel's IDT */
asm("lidt _idtr");
x86_mmu_early_init_percpu();
#if X86_WITH_FPU
x86_fpu_early_init_percpu();
#endif
}
/* early initialization of the system, on the boot cpu, usually before any sort of
* printf output is available.
*/
void arch_early_init(void) {
x86_feature_early_init();
x86_mmu_early_init();
#if X86_WITH_FPU
x86_fpu_early_init();
#endif
x86_early_init_percpu();
}
/* later initialization pass, once the main kernel is initialized and scheduling has begun */
void arch_init(void) {
x86_feature_init();
x86_mmu_init();
#if X86_WITH_FPU
x86_fpu_init();
#endif
}
void arch_chain_load(void *entry, ulong arg0, ulong arg1, ulong arg2, ulong arg3) {
PANIC_UNIMPLEMENTED;
}
void arch_enter_uspace(vaddr_t entry_point, vaddr_t user_stack_top) {
PANIC_UNIMPLEMENTED;
#if 0
DEBUG_ASSERT(IS_ALIGNED(user_stack_top, 16));
thread_t *ct = get_current_thread();
vaddr_t kernel_stack_top = (uintptr_t)ct->stack + ct->stack_size;
kernel_stack_top = ROUNDDOWN(kernel_stack_top, 16);
/* set up a default spsr to get into 64bit user space:
* zeroed NZCV
* no SS, no IL, no D
* all interrupts enabled
* mode 0: EL0t
*/
uint32_t spsr = 0;
arch_disable_ints();
asm volatile(
"mov sp, %[kstack];"
"msr sp_el0, %[ustack];"
"msr elr_el1, %[entry];"
"msr spsr_el1, %[spsr];"
"eret;"
:
: [ustack]"r"(user_stack_top),
[kstack]"r"(kernel_stack_top),
[entry]"r"(entry_point),
[spsr]"r"(spsr)
: "memory");
__UNREACHABLE;
#endif
}