void pm_init(void)
{
descriptor_t *gdt_p = (descriptor_t *) gdtr.base;
ptr_16_32_t idtr;
/*
* Update addresses in GDT and IDT to their virtual counterparts.
*/
idtr.limit = sizeof(idt);
idtr.base = (uintptr_t) idt;
gdtr_load(&gdtr);
idtr_load(&idtr);
/*
* Each CPU has its private GDT and TSS.
* All CPUs share one IDT.
*/
if (config.cpu_active == 1) {
idt_init();
/*
* NOTE: bootstrap CPU has statically allocated TSS, because
* the heap hasn't been initialized so far.
*/
tss_p = &tss0;
} else {
tss_p = (tss_t *) malloc(sizeof(tss_t), FRAME_ATOMIC);
if (!tss_p)
panic("Cannot allocate TSS.");
}
tss_initialize(tss_p);
gdt_p[TSS_DES].access = AR_PRESENT | AR_TSS | DPL_KERNEL;
gdt_p[TSS_DES].special = 1;
gdt_p[TSS_DES].granularity = 0;
gdt_setbase(&gdt_p[TSS_DES], (uintptr_t) tss_p);
gdt_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE - 1);
/*
* As of this moment, the current CPU has its own GDT pointing
* to its own TSS. We just need to load the TR register.
*/
tr_load(GDT_SELECTOR(TSS_DES));
/* Disable I/O on nonprivileged levels and clear NT flag. */
write_eflags(read_eflags() & ~(EFLAGS_IOPL | EFLAGS_NT));
/* Disable alignment check */
write_cr0(read_cr0() & ~CR0_AM);
}
/** Initialize segmentation - code/data/idt tables
*
*/
void pm_init(void)
{
descriptor_t *gdt_p = (descriptor_t *) gdtr.base;
tss_descriptor_t *tss_desc;
/*
* Each CPU has its private GDT and TSS.
* All CPUs share one IDT.
*/
if (config.cpu_active == 1) {
idt_init();
/*
* NOTE: bootstrap CPU has statically allocated TSS, because
* the heap hasn't been initialized so far.
*/
tss_p = &tss;
} else {
/* We are going to use malloc, which may return
* non boot-mapped pointer, initialize the CR3 register
* ahead of page_init */
write_cr3((uintptr_t) AS_KERNEL->genarch.page_table);
tss_p = (tss_t *) malloc(sizeof(tss_t), FRAME_ATOMIC);
if (!tss_p)
panic("Cannot allocate TSS.");
}
tss_initialize(tss_p);
tss_desc = (tss_descriptor_t *) (&gdt_p[TSS_DES]);
tss_desc->present = 1;
tss_desc->type = AR_TSS;
tss_desc->dpl = PL_KERNEL;
gdt_tss_setbase(&gdt_p[TSS_DES], (uintptr_t) tss_p);
gdt_tss_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE - 1);
gdtr_load(&gdtr);
idtr_load(&idtr);
/*
* As of this moment, the current CPU has its own GDT pointing
* to its own TSS. We just need to load the TR register.
*/
tr_load(GDT_SELECTOR(TSS_DES));
}
