Method for selecting an executable software image

• US 20040146270A1
• Filed: 03/25/2004
• Published: 07/29/2004
• Est. Priority Date: 05/09/2001
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Thomson Licensing SA (Vantiva SA)
• Inventors: Proust, Laurent, Hamery, Dominique
• Granted Patent: US 8,201,211 B2
• Time in Patent Office: Days
• US Class Current: 386/20
• CPC Class Codes: G06F 21/575 Secure boot
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/4432 Powering on the client, e.g. bootstrap loading using setup parameters being stored locally or received from the server resetting in general G06F1/14; program loading or initiating in general G06F9/445; bootstrapping in general G06F9/4401; secure boots of computer platforms G06F21/57
• CPC Class Codes: H04N 21/8173 End-user applications, e.g. Web browser, game

Abstract

Process that can be used in a digital television decoder to select and execute an image of an executable software, the process consisting of starting a self-executable boot software to load an image, the process being characterized in that a reference table is created with a cross reference to one of (n-m) images stored in a memory area without erase protection, and then following a routine carried out each time that the decoder is initialized,

v1) it is checked that the reference table is present and uncorrupted,

p) the table is read in sequence, until the stored images to which each reference corresponds are reached,

v2) it is checked that the image corresponding to the first reference reached is uncorrupted,

l) if the image checked in step c) is uncorrupted, execution of this image is started,

e) if the image that was just checked is corrupted, steps v2) and possibly l) are carried out again for the next reference, until an uncorrupted image is found,

Finally, if the table is corrupted or if all of the (n-m) images are found to be corrupted after browsing through the images stored in the memory area without erase protection, then step e) is performed for the m images stored in the areas with erase protection, these m images being read in an order defining their order of preference.

Claims

1. Process useable for example in a digital television decoder to select and run an image of an executable software, the process consisting of starting a self executable boot software stored in the equipment to run an image, the process being characterized in that the boot and load software include the following steps:

c) read a table (16) stored internally in the equipment, referencing an integer number n greater than 1 of executable software images, in a predetermined order

s) select an uncorrupted executable software image

l) start the image selected for execution.

2. Process according to claim 1, characterized in that another step is carried out before step c):

v1) check (101) that the boot software table (16) is present and uncorrupted.

3. Process according to claim 1 or 2, characterized in that the read step c) and the selection step s) comprise:

p) read (106-108) the table (16) following a predetermined order to reach the references of the table in an order of preference of the executable software images to which each reference corresponds,

v2) check (106) that a first selected image corresponding to the first reference in the table (16) reached by reading the said table, is uncorrupted, the said first image only being selected if the integrity check (106) of the said first image is positive;

e) if the first image or a previously checked image is not uncorrupted, go onto the next reference following the previous reference in the table (16) in the predetermined read order, and execute step s) (107) and possibly l) (108) if the current checked image is uncorrupted, if it is corrupted then return to step e) for the next reference in the order of reading the table (16), until an uncorrupted image is found and run.

4. Process according to claim 2, characterized in that the n images are distributed into two parts, a first part (n-m) stored in the erasable parts (25-27) of the memories and a second complementary part of the first part composed of an integer number of images m less than or equal to n stored on parts of memory (3, 23) that are not erasable or have erase protection.

5. Process according to claim 3, characterized in that the n images are distributed in two parts, a first part (n-m) stored in the erasable parts of memory (25-27) and a second part complementary to the first part composed of an integer number m of images less than or equal to n stored in parts of memory (3, 23) that are not erasable or have erase protection.

6. Process according to one of claims 4 or 5, characterized in that the references in table (16) corresponding to the (n-m) images contained in the memory areas (25-27) without erase protection are read first, and then if none of these images is selected, reading continues for the m images contained in the memory areas (3, 23) that are not erasable or that have erase protection.

7. Process according to claim 4, characterized in that when the check carried out in step v1) shows that the table (16) is corrupted, steps s), v2) and possibly l) are carried out for the m images contained in the memory areas (3, 23) that are not erasable or that have erase protection.

8. Process according to any one of claims 4 to 7, characterized in that the m images stored in the memory areas (3, 23) that are not erasable or with erase protection are stored on different media (10, 20).

9. Process according to one of claims 4 to 8, characterized in that memory areas (25-27) without erase protection in which the (n-m) images belonging to the first part are stored, are memory areas on hard disk (20).

10. Process according to one of claims 4 to 9, characterized in that the memory areas (23, 3) with erase protection in which the m images belonging to the second part are memory areas (23, 3) on the hard disk (20) or fast memory (10).

11. Process according to one of claims 1 to 10, characterized in that before one of the images is run for execution, a check is made (109) that this image is not stored in compressed mode, the image being decompressed (110) before being loaded and executed (103, 104) if it is found to be compressed.

12. Process according to one of claims 4 to 7, characterized in that an integer number n of images is loaded in a step prior to execution of the process, and distributed in a first part containing (n-m) images stored in memory areas (25-27) without erase protection and a second part containing m images stored in memory areas (3, 23) with erase protection, and in that the reference table (16) is created for the n images.

13. Digital television decoder or receiver implementing the process according to any one of the previous claims.