[parted-devel] [PATCH] mac: don't change drivers information

[Laurent Vivier]

Ping ?

Le 03/11/2015 02:11, Laurent Vivier a écrit :
> boot_region_length (or BootSize in the MacOS dialect) is the length
> of the driver code in the driver partition. This length is used
> to compute the checksum of the driver.
> 
> libparted updates this value by setting the whole size of the partition
> (why?) without computing the checksum of the driver using this size.
> 
> As the checksum is wrong, the driver is broken and cannot be loaded
> by the MacOS ROM, and thus the disk is not bootable anymore (bad!).
> 
> Moreover, parted try to update the driver list and makes it disappearing...
> 
> As parted is not able to insert a driver in a partition (is it?),
> the driver is generally inserted by the Apple HD Tool,
> this patch removes the line updating the driver size.
> 
> We also simplify the driver list scan and fix endianess use.
> 
> This has been tested... and it works, now.
> 
> I have updated a bootable disk with parted on x86_64 and
> then been able to boot it (again) on a Mac LC III.
> 
> Signed-off-by: Laurent Vivier <laurent at vivier.eu>
> ---
>  libparted/labels/mac.c | 41 ++++++++++++++++++++---------------------
>  1 file changed, 20 insertions(+), 21 deletions(-)
> 
> diff --git a/libparted/labels/mac.c b/libparted/labels/mac.c
> index d8da941..fa4e43f 100644
> --- a/libparted/labels/mac.c
> +++ b/libparted/labels/mac.c
> @@ -411,14 +411,14 @@ _rawpart_has_driver (const MacRawPartition* raw_part, MacDiskData* mac_disk_data
>  {
>  	MacDeviceDriver *driverlist;
>  	uint16_t i;
> -	uint32_t driver_bs, driver_be, part_be;
> +	uint32_t start_block, block_count;
>  
> +	start_block = PED_BE32_TO_CPU(raw_part->start_block);
> +	block_count = PED_BE32_TO_CPU(raw_part->block_count);
>  	driverlist = &mac_disk_data->driverlist[0];
>  	for (i = 0; i < mac_disk_data->driver_count; i++) {
> -		driver_bs = driverlist->block;
> -		driver_be = driver_bs + driverlist->size;
> -		part_be = raw_part->start_block + raw_part->block_count;
> -		if (driver_bs >= raw_part->start_block && driver_be <= part_be)
> +		if (start_block == PED_BE32_TO_CPU(driverlist->block) &&
> +                    block_count == PED_BE16_TO_CPU(driverlist->size))
>  			return 1;
>  		driverlist++;
>  	}
> @@ -751,11 +751,12 @@ mac_read (PedDisk* disk)
>  	if (!ped_disk_delete_all (disk))
>  		goto error;
>  
> -	if (raw_disk->driver_count && raw_disk->driver_count < 62) {
> +	if (PED_BE16_TO_CPU(raw_disk->driver_count) &&
> +            PED_BE16_TO_CPU(raw_disk->driver_count) < 62) {
>  		memcpy(&mac_disk_data->driverlist[0], &raw_disk->driverlist[0],
>  				sizeof(mac_disk_data->driverlist));
> -		mac_disk_data->driver_count = raw_disk->driver_count;
> -		mac_disk_data->block_size = raw_disk->block_size;
> +		mac_disk_data->driver_count = PED_BE16_TO_CPU(raw_disk->driver_count);
> +		mac_disk_data->block_size = PED_BE16_TO_CPU(raw_disk->block_size);
>  	}
>  
>  	/* If _disk_analyse_block_size has increased the sector_size,
> @@ -877,17 +878,16 @@ static void
>  _update_driver_count (MacRawPartition* part_map_entry,
>  		      MacDiskData *mac_driverdata, const MacDiskData* mac_disk_data)
>  {
> -	uint16_t	i, count_orig, count_cur;
> -	uint32_t	driver_bs, driver_be, part_be;
> -
> -	count_cur = mac_driverdata->driver_count;
> -	count_orig = mac_disk_data->driver_count;
> -	for (i = 0; i < count_orig; i++) {
> -		driver_bs = mac_disk_data->driverlist[i].block;
> -		driver_be = driver_bs + mac_disk_data->driverlist[i].size;
> -		part_be = part_map_entry->start_block + part_map_entry->block_count;
> -		if (driver_bs >= part_map_entry->start_block
> -				&& driver_be <= part_be) {
> +	uint16_t	i;
> +	uint32_t	start_block, block_count;
> +
> +	start_block = PED_BE32_TO_CPU(part_map_entry->start_block);
> +	block_count = PED_BE32_TO_CPU(part_map_entry->block_count);
> +
> +	for (i = 0; i < mac_disk_data->driver_count; i++) {
> +		if (start_block == PED_BE32_TO_CPU(mac_disk_data->driverlist[i].block) &&
> +		    block_count == PED_BE16_TO_CPU(mac_disk_data->driverlist[i].size)) {
> +		        uint16_t count_cur = mac_driverdata->driver_count;
>  			mac_driverdata->driverlist[count_cur].block
>  				= mac_disk_data->driverlist[i].block;
>  			mac_driverdata->driverlist[count_cur].size
> @@ -934,7 +934,6 @@ _generate_raw_part (PedDisk* disk, PedPartition* part,
>  	strncpy (part_map_entry->type, mac_part_data->system_name, 32);
>  
>  	if (mac_part_data->is_driver) {
> -		mac_part_data->boot_region_length = part->geom.length;
>  		if (mac_part_data->has_driver)
>  			_update_driver_count(part_map_entry, mac_driverdata,
>  					mac_disk_data);
> @@ -1042,7 +1041,7 @@ write_block_zero (PedDisk* disk, MacDiskData* mac_driverdata)
>  	raw_disk->block_size = PED_CPU_TO_BE16 (dev->sector_size);
>  	raw_disk->block_count = PED_CPU_TO_BE32 (dev->length);
>  
> -	raw_disk->driver_count = mac_driverdata->driver_count;
> +	raw_disk->driver_count = PED_CPU_TO_BE16(mac_driverdata->driver_count);
>  	memcpy(&raw_disk->driverlist[0], &mac_driverdata->driverlist[0],
>  			sizeof(raw_disk->driverlist));
>  
>