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Some system/debug regisiters are inconsistent with real device in qemu-system-arm
Description of problem:
We used differential testing to compared the instruction consistency (ARMv7) between QEMU and raspberry pi 2B in system level and some inconsistency in system regisiter was detected.
1. CCSIDR--Cache Size ID Registers
**Inconsistency**
- CCSIDR in QEMU: 0x701fe00a--Associativity: 2, Number of sets:256
- CCSIDR in Raspi2B: 0x700fe01a--Associativity: 4, Number of sets:128
**Tested Instruction sample**
- MRC_T1A1_A 11101110001100000000111100010000 0xee300f10
According to ARMv7 Manual B4.1.19 encoding, the NumSets and Associativity are set different bewteen QEMU when emulating raspi2b and raspi2b.
The CCSIDR is set in the function`cortex_a7_initfn(Object *obj)` in target/arm/cpu_tcg.c for cortex_a7.
2. DBGDRAR--Debug ROM Address Register
**Inconsistency**
- DBGDRAR in QEMU: 0x0 --Invalid
- DBGDRAR in Raspi2B: 0x40020003--Valid
According to ARMv7 Manual C11.11.16 encoding, the DBGDRAR in qemu is invalid.
**Tested Instruction sample**
- MRC_T1A1_A 11101110000100010001111000010000 0xee111e10
Steps to reproduce:
1. Compile a kernel module to run the test instruction in PL1.
2. Use kgdb to get the register info
Additional information:
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