target-arm: A64: Implement minimal set of EL0-visible sysregs

Implement an initial minimal set of EL0-visible system registers:
 * NZCV
 * FPCR
 * FPSR
 * CTR_EL0
 * DCZID_EL0

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
This commit is contained in:
Peter Maydell 2014-01-04 22:15:45 +00:00
parent fea505221e
commit b0d2b7d0f0
3 changed files with 115 additions and 1 deletions

View file

@ -733,6 +733,50 @@ static void handle_msr_i(DisasContext *s, uint32_t insn,
unsupported_encoding(s, insn);
}
static void gen_get_nzcv(TCGv_i64 tcg_rt)
{
TCGv_i32 tmp = tcg_temp_new_i32();
TCGv_i32 nzcv = tcg_temp_new_i32();
/* build bit 31, N */
tcg_gen_andi_i32(nzcv, cpu_NF, (1 << 31));
/* build bit 30, Z */
tcg_gen_setcondi_i32(TCG_COND_EQ, tmp, cpu_ZF, 0);
tcg_gen_deposit_i32(nzcv, nzcv, tmp, 30, 1);
/* build bit 29, C */
tcg_gen_deposit_i32(nzcv, nzcv, cpu_CF, 29, 1);
/* build bit 28, V */
tcg_gen_shri_i32(tmp, cpu_VF, 31);
tcg_gen_deposit_i32(nzcv, nzcv, tmp, 28, 1);
/* generate result */
tcg_gen_extu_i32_i64(tcg_rt, nzcv);
tcg_temp_free_i32(nzcv);
tcg_temp_free_i32(tmp);
}
static void gen_set_nzcv(TCGv_i64 tcg_rt)
{
TCGv_i32 nzcv = tcg_temp_new_i32();
/* take NZCV from R[t] */
tcg_gen_trunc_i64_i32(nzcv, tcg_rt);
/* bit 31, N */
tcg_gen_andi_i32(cpu_NF, nzcv, (1 << 31));
/* bit 30, Z */
tcg_gen_andi_i32(cpu_ZF, nzcv, (1 << 30));
tcg_gen_setcondi_i32(TCG_COND_EQ, cpu_ZF, cpu_ZF, 0);
/* bit 29, C */
tcg_gen_andi_i32(cpu_CF, nzcv, (1 << 29));
tcg_gen_shri_i32(cpu_CF, cpu_CF, 29);
/* bit 28, V */
tcg_gen_andi_i32(cpu_VF, nzcv, (1 << 28));
tcg_gen_shli_i32(cpu_VF, cpu_VF, 3);
tcg_temp_free_i32(nzcv);
}
/* C5.6.129 MRS - move from system register
* C5.6.131 MSR (register) - move to system register
* C5.6.204 SYS
@ -767,6 +811,14 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
switch (ri->type & ~(ARM_CP_FLAG_MASK & ~ARM_CP_SPECIAL)) {
case ARM_CP_NOP:
return;
case ARM_CP_NZCV:
tcg_rt = cpu_reg(s, rt);
if (isread) {
gen_get_nzcv(tcg_rt);
} else {
gen_set_nzcv(tcg_rt);
}
return;
default:
break;
}