Skip to main content

Table 4 Total binary sizes of the system components together with measurement runtimes (average over 100 runs) using the SHA1 hash algorithm. The increase of binary size over for the additional measurement and TPM code is given in brackets. The OMAP internal ROM code is less than 32 kB but the exact size is unknown. To measure the second bootloader stage (X-Loader), the ROM code could be extended with a software SHA1 implementation running on the OMAP CPU or it could use the TPM's SHA1 engine. Following the boot sequence outlined in Section 5.1, components are measured by the previous bootloader stage before control is passed on. The OMAP ROM code acts as root of trust and is not measured.

From: Securing Embedded Smart Cameras with Trusted Computing

  Binary Size Measurement Runtime
ROM Code plus SHA1 on OMAP and TPM_Extend 32. 0 kB (+ 8.0 kB) n/a
ROM Code plus SHA1 onTPM and TPM_Extend 32.0kB(+ 1. 1 kB) n/a
X-Loader 1.4.2 plus SHA1 and TPM_Extend 28.5 kB(+ 7. 8 kB) 1.6 ms (OMAP)
   5869.6 ms (TPM)
U-Boot 2009.06 plus TPM_Extend 177. 0 kB(+ 0. 9 kB) 8.3 ms
Linux Kernel 2.6.34 2. 1 MB 96.0 ms
Kernel Parameters 1. 0 kB 0.3 ms
Root Filesystem 26. 2 MB 1157. 4 ms
Total n/a 1263.6 ms (OMAP)
   7131.6 ms (TPM)