init.c

/* SPDX-License-Identifier: MIT */

#include "x86.h"
#include <init.h>
#include <stddef.h>
#include <stdint.h>

/* kernel.lds.S */
extern init_stage_hook_t __init_hooks_start[];
extern init_stage_hook_t __init_hooks_end[];

/* current stage hook */
static __init_data init_stage_hook_t *init_hook_cur = __init_hooks_start;
/* current initialization stage */
init_stage_t                          stage = INIT_STAGE_NONE;

static int __init_func hook_cmp(const void *hook1, const void *hook2)
{
    const init_stage_hook_t *a = hook1;
    const init_stage_hook_t *b = hook2;

    if (a->stage == b->stage) {
        if (a->priority == b->priority) {
            return 0;
        }
        return a->priority < b->priority ? -1 : 1;
    }
    return a->stage < b->stage ? -1 : 1;
}

extern void qsort(void *arr, size_t n, size_t es,
                  int (*cmp)(const void *, const void *));

void __init_func init_hooks_init(void)
{
    size_t num_hooks = __init_hooks_end - __init_hooks_start;

    if (((uintptr_t)__init_hooks_end - (uintptr_t)__init_hooks_start) %
        sizeof(init_stage_hook_t)) {
        /* error the size does not fit the struct */
    }

    /* sort the hooks in level of their stages */
    qsort(__init_hooks_start, num_hooks, sizeof(init_stage_hook_t), hook_cmp);
}

void __init_func kernel_init_upto(init_stage_t upto_stage)
{
    init_stage_hook_t *cur_hook = init_hook_cur;

    while (cur_hook < __init_hooks_end && cur_hook->stage <= upto_stage) {
        if (stage >= INIT_STAGE_KPRINTF) {
            /* kprintf("%s[%d]: %p(%p)", __func__, cur_hook->stage,
             * cur_hook->hook, */
            /*         cur_hook->args); */
        }
        stage = cur_hook->stage - 1;
        cur_hook->hook(cur_hook->args);
        init_hook_cur = ++cur_hook;
    }

    if (upto_stage >= INIT_STAGE_KPRINTF) {
        /* kprintf("reached stage %d\n", upto_stage); */
    }

    stage = upto_stage;
}

void __init_func init_test1()
{
    /* __asm__ volatile("int3"); */
}

REGISTER_INIT_HOOK(test1, KPRINTF, 1, &init_test1, NULL);