From 14120108f87b3f9e1beacdf0a6096e464e62bb65 Mon Sep 17 00:00:00 2001 From: Julia Suvorova Date: Fri, 15 Jun 2018 14:57:16 +0100 Subject: target/arm: Allow ARMv6-M Thumb2 instructions ARMv6-M supports 6 Thumb2 instructions. This patch checks for these instructions and allows their execution. Like Thumb2 cores, ARMv6-M always interprets BL instruction as 32-bit. This patch is required for future Cortex-M0 support. Signed-off-by: Julia Suvorova Reviewed-by: Stefan Hajnoczi Message-id: 20180612204632.28780-1-jusual@mail.ru [PMM: move armv6m_insn[] and armv6m_mask[] closer to point of use, and mark 'const'. Check for M-and-not-v7 rather than M-and-6.] Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- target/arm/translate.c | 43 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 5 deletions(-) diff --git a/target/arm/translate.c b/target/arm/translate.c index 0ff5edf2ce..f405c82fb2 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -9965,7 +9965,8 @@ static bool thumb_insn_is_16bit(DisasContext *s, uint32_t insn) * end up actually treating this as two 16-bit insns, though, * if it's half of a bl/blx pair that might span a page boundary. */ - if (arm_dc_feature(s, ARM_FEATURE_THUMB2)) { + if (arm_dc_feature(s, ARM_FEATURE_THUMB2) || + arm_dc_feature(s, ARM_FEATURE_M)) { /* Thumb2 cores (including all M profile ones) always treat * 32-bit insns as 32-bit. */ @@ -10085,10 +10086,38 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn) int conds; int logic_cc; - /* The only 32 bit insn that's allowed for Thumb1 is the combined - * BL/BLX prefix and suffix. + /* + * ARMv6-M supports a limited subset of Thumb2 instructions. + * Other Thumb1 architectures allow only 32-bit + * combined BL/BLX prefix and suffix. */ - if ((insn & 0xf800e800) != 0xf000e800) { + if (arm_dc_feature(s, ARM_FEATURE_M) && + !arm_dc_feature(s, ARM_FEATURE_V7)) { + int i; + bool found = false; + const uint32_t armv6m_insn[] = {0xf3808000 /* msr */, + 0xf3b08040 /* dsb */, + 0xf3b08050 /* dmb */, + 0xf3b08060 /* isb */, + 0xf3e08000 /* mrs */, + 0xf000d000 /* bl */}; + const uint32_t armv6m_mask[] = {0xffe0d000, + 0xfff0d0f0, + 0xfff0d0f0, + 0xfff0d0f0, + 0xffe0d000, + 0xf800d000}; + + for (i = 0; i < ARRAY_SIZE(armv6m_insn); i++) { + if ((insn & armv6m_mask[i]) == armv6m_insn[i]) { + found = true; + break; + } + } + if (!found) { + goto illegal_op; + } + } else if ((insn & 0xf800e800) != 0xf000e800) { ARCH(6T2); } @@ -11009,7 +11038,11 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn) } break; case 3: /* Special control operations. */ - ARCH(7); + if (!arm_dc_feature(s, ARM_FEATURE_V7) && + !(arm_dc_feature(s, ARM_FEATURE_V6) && + arm_dc_feature(s, ARM_FEATURE_M))) { + goto illegal_op; + } op = (insn >> 4) & 0xf; switch (op) { case 2: /* clrex */ -- cgit v1.2.3