/*
** Copyright 2003-2004, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
** Distributed under the terms of the OpenBeOS License.
*/


#include "loader.h"
#include "elf.h"
#include "RootFileSystem.h"

#include <OS.h>
#include <util/list.h>
#include <boot/stage2.h>
#include <boot/vfs.h>
#include <boot/platform.h>
#include <boot/stdio.h>
#include <boot/partitions.h>

#include <unistd.h>
#include <string.h>

#ifndef BOOT_ARCH
#	error BOOT_ARCH has to be defined to differentiate the kernel per platform
#endif

#define KERNEL_IMAGE	"kernel_" BOOT_ARCH
#define KERNEL_PATH		"beos/system/" KERNEL_IMAGE


// temp. VFS API
extern Node *get_node_from(int fd);


static const char *sPaths[] = {
	"beos/system/add-ons/kernel",
	"home/config/add-ons/kernel",
	NULL
};


bool
is_bootable(Directory *volume)
{
	if (volume->IsEmpty())
		return false;

	// check for the existance of a kernel (for our platform)
	int fd = open_from(volume, KERNEL_PATH, O_RDONLY);
	if (fd < B_OK)
		return false;

	close(fd);

	return true;
}


status_t 
load_kernel(stage2_args *args, Directory *volume)
{
	int fd = open_from(volume, KERNEL_PATH, O_RDONLY);
	if (fd < B_OK)
		return fd;

	puts("load kernel...");

	status_t status = elf_load_image(fd, &gKernelArgs.kernel_image);

	close(fd);

	if (status < B_OK) {
		printf("loading kernel failed: %ld!\n", status);
		return status;
	}

	puts("kernel loaded successfully");
	return B_OK;
}


static status_t
load_modules_from(Directory *volume, const char *path)
{
	// we don't have readdir() & co. (yet?)...

	int fd = open_from(volume, path, O_RDONLY);
	if (fd < B_OK)
		return fd;

	Directory *modules = (Directory *)get_node_from(fd);
	if (modules == NULL)
		return B_ENTRY_NOT_FOUND;

	void *cookie;
	if (modules->Open(&cookie, O_RDONLY) == B_OK) {
		char name[B_FILE_NAME_LENGTH];
		while (modules->GetNextEntry(cookie, name, sizeof(name)) == B_OK) {
			if (!strcmp(name, ".") || !strcmp(name, ".."))
				continue;

			status_t status = elf_load_image(modules, name);
			if (status != B_OK)
				dprintf("Could not load \"%s\" error %ld\n", name, status);
		}

		modules->Close(cookie);
	}

	return B_OK;
}


/** Loads a module by module name. This basically works in the same
 *	way as the kernel module loader; it will cut off the last part
 *	of the module name until it could find a module and loads it.
 *	It tests both, kernel and user module directories.
 */

static status_t
load_module(Directory *volume, const char *name)
{
	char moduleName[B_FILE_NAME_LENGTH];
	if (strlcpy(moduleName, name, sizeof(moduleName)) > sizeof(moduleName))
		return B_NAME_TOO_LONG;

	for (int32 i = 0; sPaths[i]; i++) {
		// get base path
		int baseFD = open_from(volume, sPaths[i], O_RDONLY);
		if (baseFD < B_OK)
			continue;

		Directory *base = (Directory *)get_node_from(baseFD);

		while (true) {
			int fd = open_from(base, moduleName, O_RDONLY);
			if (fd >= B_OK) {
				status_t status = elf_load_image(base, moduleName);

				close(fd);
				close(baseFD);
				return status;
			}

			// cut off last name element (or stop trying if there are no more)

			char *last = strrchr(moduleName, '/');
			if (last != NULL)
				last[0] = '\0';
			else
				break;
		}

		close(baseFD);
	}

	return B_OK;
}


status_t 
load_modules(stage2_args *args, Directory *volume)
{
	for (int32 i = 0; sPaths[i]; i++) {
		char path[B_FILE_NAME_LENGTH];
		sprintf(path, "%s/boot", sPaths[i]);

		load_modules_from(volume, path);
	}

	// and now load all partitioning and file system modules
	// needed to identify the boot volume

	Partition *partition;
	if (gRoot->GetPartitionFor(volume, &partition) == B_OK) {
		while (partition != NULL) {
			load_module(volume, partition->ModuleName());
			partition = partition->Parent();
		}
	}

	return B_OK;
}