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| author | Leon Alrae <leon.alrae@imgtec.com> | 2016-02-24 10:47:10 +0000 |
|---|---|---|
| committer | Leon Alrae <leon.alrae@imgtec.com> | 2016-03-23 13:36:55 +0000 |
| commit | ba5c79f26221c0fd7139c883a34a4e75d993f732 (patch) | |
| tree | 89fdd4d5eb8e135b8f78f5ad34a78c622f25f6d3 /target-mips/cpu.h | |
| parent | ffa6564c9b13cea4b704e184d29d721f2cb061bb (diff) | |
target-mips: indicate presence of IEEE 754-2008 FPU in R6/R5+MSA CPUs
MIPS Release 6 and MIPS SIMD Architecture make it mandatory to have IEEE
754-2008 FPU which is indicated by CP1 FIR.HAS2008, FCSR.ABS2008 and
FCSR.NAN2008 bits set to 1.
In QEMU we still keep these bits cleared as there is no 2008-NaN support.
However, this now causes problems preventing from running R6 Linux with
the v4.5 kernel. Kernel refuses to execute 2008-NaN ELFs on a CPU
whose FPU does not support 2008-NaN encoding:
(...)
VFS: Mounted root (ext4 filesystem) readonly on device 8:0.
devtmpfs: mounted
Freeing unused kernel memory: 256K (ffffffff806f0000 - ffffffff80730000)
request_module: runaway loop modprobe binfmt-464c
Starting init: /sbin/init exists but couldn't execute it (error -8)
request_module: runaway loop modprobe binfmt-464c
Starting init: /bin/sh exists but couldn't execute it (error -8)
Kernel panic - not syncing: No working init found. Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.
Therefore always indicate presence of 2008-NaN support in R6 as well as in
R5+MSA CPUs, even though this feature is not yet supported by MIPS in QEMU.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Diffstat (limited to 'target-mips/cpu.h')
| -rw-r--r-- | target-mips/cpu.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/target-mips/cpu.h b/target-mips/cpu.h index 1e2b070cc3..4f3ebb9dbb 100644 --- a/target-mips/cpu.h +++ b/target-mips/cpu.h @@ -99,6 +99,7 @@ struct CPUMIPSFPUContext { uint32_t fcr0; #define FCR0_FREP 29 #define FCR0_UFRP 28 +#define FCR0_HAS2008 23 #define FCR0_F64 22 #define FCR0_L 21 #define FCR0_W 20 @@ -110,6 +111,8 @@ struct CPUMIPSFPUContext { #define FCR0_REV 0 /* fcsr */ uint32_t fcr31; +#define FCR31_ABS2008 19 +#define FCR31_NAN2008 18 #define SET_FP_COND(num,env) do { ((env).fcr31) |= ((num) ? (1 << ((num) + 24)) : (1 << 23)); } while(0) #define CLEAR_FP_COND(num,env) do { ((env).fcr31) &= ~((num) ? (1 << ((num) + 24)) : (1 << 23)); } while(0) #define GET_FP_COND(env) ((((env).fcr31 >> 24) & 0xfe) | (((env).fcr31 >> 23) & 0x1)) |