src/kernel/fs/iso9660/iso9660.c


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#include <stdint.h>
#include <kernel/fs/atapi_pio.h>
#include <kernel/fs/iso9660/iso9660.h>
#include <kernel/lib/stdlib.h>
#include <kernel/memory/alloc.h>

struct iso9660_entity *ISO9660_get(char **dirs, uint8_t dirs_sz)
{
	ATAPI_read(1, 0x10);
	uint32_t last_len = *(uint32_t *)(ATAPI_PIO_BUFFER + ISO9660_ROOT_RECORD_OFFSET +
					  ISO9660_DIR_EAR_LENGTH);
	uint32_t last_lba =
		*(uint32_t *)(ATAPI_PIO_BUFFER + ISO9660_ROOT_RECORD_OFFSET + ISO9660_DIR_EAR_LBA);

	for (uint8_t dirs_i = 0; dirs_i < dirs_sz; dirs_i++) {
		ATAPI_read((last_len % 2048 != 0) + (last_len / 2048), last_lba);

		uint8_t found = 0;
		for (uint32_t i = 0; i < last_len && !found;) {
			if (!*(uint8_t *)(ATAPI_PIO_BUFFER + i + ISO9660_DIR_RECORD_LENGTH))
				break;

			char *filename = (char *)(ATAPI_PIO_BUFFER + i + ISO9660_DIR_FILENAME);

			for (uint32_t j = 0; j < ISO9660_DIR_FILENAME_LENGTH; j++) {
				if (filename[j] == ';') {
					filename[j] = 0;
					break;
				}
			}

			if (strcmp(dirs[dirs_i], filename) == 0) {
				found = 1;
				last_lba =
					*(uint32_t *)(ATAPI_PIO_BUFFER + i + ISO9660_DIR_EAR_LBA);
				last_len = *(uint32_t *)(ATAPI_PIO_BUFFER + i +
							 ISO9660_DIR_EAR_LENGTH);
			} else {
				i += *(uint8_t *)(ATAPI_PIO_BUFFER + i + ISO9660_DIR_RECORD_LENGTH);
			}
		}

		if (!found) {
			return (struct iso9660_entity *)0;
		}
	}

	struct iso9660_entity *ret =
		(struct iso9660_entity *)kmalloc(sizeof(struct iso9660_entity));
	ret->lba = last_lba;
	ret->length = last_len;
	return ret;
}

uint8_t *ISO9660_read(struct iso9660_entity *entity)
{
	ATAPI_read((entity->length % 2048 != 0) + (entity->length / 2048), entity->lba);
	return (uint8_t *)ATAPI_PIO_BUFFER;
}