mips: Add M14K and M14Kc MIPS32r2 microMIPS processors

Add the M14K and M14Kc processors from MIPS Technologies that are the 
original implementation of the microMIPS ISA.  They are dual instruction 
set processors, implementing both the microMIPS and the standard MIPSr32 
ISA.

These processors correspond to the M4K and 4KEc CPUs respectively, 
except with support for the microMIPS instruction set added, support for 
the MCU ASE added and two extra interrupt lines, making a total of 8 
hardware interrupts plus 2 software interrupts.  The remaining parts of 
the microarchitecture, in particular the pipeline, stayed unchanged.

The presence of the microMIPS ASE is is reflected in the configuration 
added.  We currently have no support for the MCU ASE, including in 
particular the ACLR, ASET and IRET instructions in either encoding, and 
we have no support for the extra interrupt lines, including bits in 
CP0.Status and CP0.Cause registers, so these features are not marked, 
making our support diverge from real hardware.

Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
---
 Hopefully we'll get the missing features sometime sooner rather than 
later, they should not be difficult to add.  Meanwhile having actual 
microMIPS CPUs to select is I think a worthwhile addition.  Please 
apply.

  Maciej

qemu-mips-m14k.diff

On 04/11/2014 15:39, Maciej W. Rozycki wrote:
> Add the M14K and M14Kc processors from MIPS Technologies that are the 
> original implementation of the microMIPS ISA.  They are dual instruction 
> set processors, implementing both the microMIPS and the standard MIPSr32 
> ISA.
> 
> These processors correspond to the M4K and 4KEc CPUs respectively, 
> except with support for the microMIPS instruction set added, support for 
> the MCU ASE added and two extra interrupt lines, making a total of 8 
> hardware interrupts plus 2 software interrupts.  The remaining parts of 
> the microarchitecture, in particular the pipeline, stayed unchanged.
> 
> The presence of the microMIPS ASE is is reflected in the configuration 
> added.  We currently have no support for the MCU ASE, including in 
> particular the ACLR, ASET and IRET instructions in either encoding, and 
> we have no support for the extra interrupt lines, including bits in 
> CP0.Status and CP0.Cause registers, so these features are not marked, 
> making our support diverge from real hardware.
> 
> Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
> Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
> ---
>  Hopefully we'll get the missing features sometime sooner rather than 
> later, they should not be difficult to add.  Meanwhile having actual 
> microMIPS CPUs to select is I think a worthwhile addition.  Please 
> apply.
> 
>   Maciej
> 
> qemu-mips-m14k.diff
> Index: qemu-git-trunk/target-mips/translate_init.c
> ===================================================================
> --- qemu-git-trunk.orig/target-mips/translate_init.c	2014-11-03 19:09:06.000000000 +0000
> +++ qemu-git-trunk/target-mips/translate_init.c	2014-11-04 00:33:42.268947442 +0000
> @@ -344,6 +344,47 @@ static const mips_def_t mips_defs[] =
>          .mmu_type = MMU_TYPE_R4000,
>      },
>      {
> +        .name = "M14K",
> +        .CP0_PRid = 0x00019b00,
> +        /* Config1 implemented, fixed mapping MMU,
> +           no virtual icache, uncached coherency. */
> +        .CP0_Config0 = MIPS_CONFIG0 | (0x2 << CP0C0_KU) | (0x2 << CP0C0_K23) |
> +                       (0x1 << CP0C0_AR) | (MMU_TYPE_FMT << CP0C0_MT),
> +        .CP0_Config1 = MIPS_CONFIG1,
> +        .CP0_Config2 = MIPS_CONFIG2,
> +        .CP0_Config3 = MIPS_CONFIG3 | (0x2 << CP0C3_ISA) | (1 << CP0C3_VInt),
> +        .CP0_LLAddr_rw_bitmask = 0,
> +        .CP0_LLAddr_shift = 4,
> +        .SYNCI_Step = 32,
> +        .CCRes = 2,
> +        .CP0_Status_rw_bitmask = 0x1258FF17,
> +        .SEGBITS = 32,
> +        .PABITS = 32,
> +        .insn_flags = CPU_MIPS32R2 | ASE_MICROMIPS,
> +        .mmu_type = MMU_TYPE_FMT,
> +    },
> +    {
> +        .name = "M14Kc",
> +        /* This is the TLB-based MMU core.  */
> +        .CP0_PRid = 0x00019c00,
> +        .CP0_Config0 = MIPS_CONFIG0 | (0x1 << CP0C0_AR) |
> +                       (MMU_TYPE_R4000 << CP0C0_MT),
> +        .CP0_Config1 = MIPS_CONFIG1 | (15 << CP0C1_MMU) |
> +                       (0 << CP0C1_IS) | (3 << CP0C1_IL) | (1 << CP0C1_IA) |
> +                       (0 << CP0C1_DS) | (3 << CP0C1_DL) | (1 << CP0C1_DA),
> +        .CP0_Config2 = MIPS_CONFIG2,
> +        .CP0_Config3 = MIPS_CONFIG3 | (0x2 << CP0C3_ISA) | (0 << CP0C3_VInt),
> +        .CP0_LLAddr_rw_bitmask = 0,
> +        .CP0_LLAddr_shift = 4,
> +        .SYNCI_Step = 32,
> +        .CCRes = 2,
> +        .CP0_Status_rw_bitmask = 0x1278FF17,
> +        .SEGBITS = 32,
> +        .PABITS = 32,
> +        .insn_flags = CPU_MIPS32R2 | ASE_MICROMIPS,
> +        .mmu_type = MMU_TYPE_R4000,
> +    },
> +    {
>          /* A generic CPU providing MIPS32 Release 5 features.
>             FIXME: Eventually this should be replaced by a real CPU model. */
>          .name = "mips32r5-generic",
> 

The actual microMIPS CPU definition is indeed a worthwile addition -
thanks. It was on my TODO list to upstream such a CPU but I haven't got
round to it.

Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>

Regards,
Leon

On Wed, 5 Nov 2014, Leon Alrae wrote:

> The actual microMIPS CPU definition is indeed a worthwile addition -
> thanks. It was on my TODO list to upstream such a CPU but I haven't got
> round to it.

 You may still be able to contribute here, by adding microMIPS DSP CPUs.  
Regrettably I wasn't able to track down documentation for the M14KE and 
M14KEc cores or I would have submitted entries for them too; I'd need 
the values of CP0.PRId at the very least, although I presume otherwise 
they're just like the M14K and M14Kc with the CP0.Config3.DSP and 
CP0.Config3.DSP2P bits set (that of course also implies CP0.Status.MX 
being writable).

 Thanks for your review.

  Maciej