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| author | Peter Maydell <peter.maydell@linaro.org> | 2011-02-22 18:19:43 +0000 |
|---|---|---|
| committer | Aurelien Jarno <aurelien@aurel32.net> | 2011-03-07 09:46:19 +0100 |
| commit | ca27c052d992da83ce0786d81f85b87cd1f5d301 (patch) | |
| tree | 4ea796f79b4bfc9b090eb6c15ed85763203fb2e2 | |
| parent | 3849902cd852d7de0783abc41cb0c57949d567fd (diff) | |
| download | qemu-ca27c052d992da83ce0786d81f85b87cd1f5d301.zip qemu-ca27c052d992da83ce0786d81f85b87cd1f5d301.tar.gz qemu-ca27c052d992da83ce0786d81f85b87cd1f5d301.tar.bz2 | |
target-arm: Implement a minimal set of cp14 debug registers
Newer ARM kernels try to probe for whether the CPU has hardware breakpoint
support. For this to work QEMU has to implement a minimal set of the cp14
debug registers. The architecture requires v7 cores to implement debug
and so there is no defined way to report its absence; however in practice
returning a zero DBGDIDR (ie with a reserved value for "debug architecture
version") should cause well-written hw debug users to do the right thing.
We also implement DBGDRAR and DBGDSAR as RAZ, indicating no memory mapped
debug components.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
| -rw-r--r-- | target-arm/translate.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/target-arm/translate.c b/target-arm/translate.c index 91203c2..062de5e 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -5778,6 +5778,34 @@ static int disas_cp14_read(CPUState * env, DisasContext *s, uint32_t insn) int rt = (insn >> 12) & 0xf; TCGv tmp; + /* Minimal set of debug registers, since we don't support debug */ + if (op1 == 0 && crn == 0 && op2 == 0) { + switch (crm) { + case 0: + /* DBGDIDR: just RAZ. In particular this means the + * "debug architecture version" bits will read as + * a reserved value, which should cause Linux to + * not try to use the debug hardware. + */ + tmp = tcg_const_i32(0); + store_reg(s, rt, tmp); + return 0; + case 1: + case 2: + /* DBGDRAR and DBGDSAR: v7 only. Always RAZ since we + * don't implement memory mapped debug components + */ + if (ENABLE_ARCH_7) { + tmp = tcg_const_i32(0); + store_reg(s, rt, tmp); + return 0; + } + break; + default: + break; + } + } + if (arm_feature(env, ARM_FEATURE_THUMB2EE)) { if (op1 == 6 && crn == 0 && crm == 0 && op2 == 0) { /* TEECR */ |