diff options
| -rw-r--r-- | target/mips/translate_init.inc.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/target/mips/translate_init.inc.c b/target/mips/translate_init.inc.c index acab097820..85da4a269c 100644 --- a/target/mips/translate_init.inc.c +++ b/target/mips/translate_init.inc.c @@ -411,6 +411,65 @@ const mips_def_t mips_defs[] = .mmu_type = MMU_TYPE_R4000, }, { + /* + * The Toshiba TX System RISC TX79 Core Architecture manual + * + * https://wiki.qemu.org/File:C790.pdf + * + * describes the C790 processor that is a follow-up to the R5900. + * There are a few notable differences in that the R5900 FPU + * + * - is not IEEE 754-1985 compliant, + * - does not implement double format, and + * - its machine code is nonstandard. + */ + .name = "R5900", + .CP0_PRid = 0x00002E00, + /* No L2 cache, icache size 32k, dcache size 32k, uncached coherency. */ + .CP0_Config0 = (0x3 << 9) | (0x3 << 6) | (0x2 << CP0C0_K0), + .CP0_Status_rw_bitmask = 0xF4C79C1F, +#ifdef CONFIG_USER_ONLY + /* + * R5900 hardware traps to the Linux kernel for IEEE 754-1985 and LL/SC + * emulation. For user only, QEMU is the kernel, so we emulate the traps + * by simply emulating the instructions directly. + * + * Note: Config1 is only used internally, the R5900 has only Config0. + */ + .CP0_Config1 = (1 << CP0C1_FP) | (47 << CP0C1_MMU), + .CP0_LLAddr_rw_bitmask = 0xFFFFFFFF, + .CP0_LLAddr_shift = 4, + .CP1_fcr0 = (0x38 << FCR0_PRID) | (0x0 << FCR0_REV), + .CP1_fcr31 = 0, + .CP1_fcr31_rw_bitmask = 0x0183FFFF, +#else + /* + * The R5900 COP1 FPU implements single-precision floating-point + * operations but is not entirely IEEE 754-1985 compatible. In + * particular, + * + * - NaN (not a number) and +/- infinities are not supported; + * - exception mechanisms are not fully supported; + * - denormalized numbers are not supported; + * - rounding towards nearest and +/- infinities are not supported; + * - computed results usually differs in the least significant bit; + * - saturations can differ more than the least significant bit. + * + * Since only rounding towards zero is supported, the two least + * significant bits of FCR31 are hardwired to 01. + * + * FPU emulation is disabled here until it is implemented. + * + * Note: Config1 is only used internally, the R5900 has only Config0. + */ + .CP0_Config1 = (47 << CP0C1_MMU), +#endif /* !CONFIG_USER_ONLY */ + .SEGBITS = 32, + .PABITS = 32, + .insn_flags = CPU_R5900 | ASE_MMI, + .mmu_type = MMU_TYPE_R4000, + }, + { /* A generic CPU supporting MIPS32 Release 6 ISA. FIXME: Support IEEE 754-2008 FP. Eventually this should be replaced by a real CPU model. */ |