The restricted opcode is not so unusual. We have encountered the same with some thinkpads. Vendors don't need proper RDID because they usually know which chip is installed so they don't have to support 300+ chips like flashrom does.
On Mon, 29 Apr 2013 14:47:35 +0400 Vasiliy Vylegzhanin 6vasia@gmail.com wrote:
0x54: 0x00000000 FREG0: Flash Descriptor region (0x00000000-0x00000fff) is read-write. 0x58: 0x07ff0580 FREG1: BIOS region (0x00580000-0x007fffff) is read-write. 0x5C: 0x057f0003 FREG2: Management Engine region (0x00003000-0x0057ffff) is read-write. 0x60: 0x00020001 FREG3: Gigabit Ethernet region (0x00001000-0x00002fff) is read-write. 0x64: 0x00000fff FREG4: Platform Data region is unused. 0x74: 0x00000000 (PR0 is unused) 0x78: 0x00000000 (PR1 is unused) 0x7C: 0x00000000 (PR2 is unused) 0x80: 0x87ff0770 PR3: WARNING: 0x00770000-0x007fffff is read-only. 0x84: 0x875f0580 PR4: WARNING: 0x00580000-0x0075ffff is read-only.
The protected regions are a bigger problem. This configuration protects almost the complete BIOS region and this can not be disabled at runtime. Does the vendor offer updates for the BIOS? Did you look into the BIOS configuration menu if there is a switch to allow BIOS modifications?