RossComputerGuy/stardustos

/**
 * NewLand Kernel - (C) 2019 Tristan Ross
 */
#include <newland/log.h>
#include <newland/module.h>
#include <newland/errno.h>
#include <stdint.h>

SLIST_HEAD(modlist, modinfo_t);

extern modinfo_t __modules_start[] __attribute__((weak));
extern modinfo_t __modules_end[] __attribute__((weak));
static size_t modcount = 0;
static struct modlist modules_installed = { NULL };
static struct modlist modules_loaded = { NULL };

modinfo_t* module_fromid(const char* id) {
    modinfo_t* module = NULL;
    SLIST_FOREACH(module, &modules_installed, mod_installed) {
        if (!strcmp(module->id, id)) return module;
    }
    return NULL;
}

int modules_init() {
/** Install the modules from the binary into the list **/
    size_t mc = (((uintptr_t)&__modules_end) - ((uintptr_t)&__modules_start)) / sizeof(modinfo_t);
    printk(KLOG_INFO "modules: loading %d kernel modules\n", mc);
    for (size_t i = 0; i < mc; i++) {
        modinfo_t* mod = (modinfo_t*)(((uintptr_t)&__modules_start) + (sizeof(modinfo_t) * i));
        int r = module_install(mod);
        if (r < 0) return r;
    }

/** Initialize the modules **/
    modinfo_t* module = NULL;
    SLIST_FOREACH(module, &modules_installed, mod_installed) {
        int r = module_init(module->id);
        if (r < 0) return r;
    }
    return 0;
}

int module_install(modinfo_t* module) {
    if (module_fromid(module->id) != NULL) return -NEWLAND_EEXIST;

    module->mod_installed.sle_next = NULL;
    module->mod_loaded.sle_next = NULL;

    SLIST_INSERT_HEAD(&modules_installed, module, mod_installed);
    return 0;
}

int module_init(const char* id) {
    modinfo_t* module = module_fromid(id);
    if (module == NULL) return -NEWLAND_ENOENT;
    if (module->mod_loaded.sle_next != NULL) return 0;
    int r = 0;
    if (module->deps != NULL) {
        size_t i = 0;
        while (module->deps[i++] != NULL) {
            r = module_init(module->deps[i - 1]);
            if (r < 0) return r;
        }
    }
    r = module->init();
    if (r < 0) return r;
    SLIST_INSERT_HEAD(&modules_loaded, module, mod_loaded);
    return r;
}