From 6abcec36741e589c855084e59195fc3454bf4be6 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Sun, 7 Mar 2021 22:25:52 +0100 Subject: target/m68k: implement rtr instruction This is needed to boot MacOS ROM. Pull the condition code and the program counter from the stack. Operation: (SP) -> CCR SP + 2 -> SP (SP) -> PC SP + 4 -> SP This operation is not privileged. Reported-by: Mark Cave-Ayland Tested-by: Mark Cave-Ayland Signed-off-by: Laurent Vivier Reviewed-by: Richard Henderson Message-Id: <20210307212552.523552-1-laurent@vivier.eu> --- target/m68k/translate.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/target/m68k/translate.c b/target/m68k/translate.c index ac936eb..200018a 100644 --- a/target/m68k/translate.c +++ b/target/m68k/translate.c @@ -2969,6 +2969,25 @@ DISAS_INSN(rtd) gen_jmp(s, tmp); } +DISAS_INSN(rtr) +{ + TCGv tmp; + TCGv ccr; + TCGv sp; + + sp = tcg_temp_new(); + ccr = gen_load(s, OS_WORD, QREG_SP, 0, IS_USER(s)); + tcg_gen_addi_i32(sp, QREG_SP, 2); + tmp = gen_load(s, OS_LONG, sp, 0, IS_USER(s)); + tcg_gen_addi_i32(QREG_SP, sp, 4); + tcg_temp_free(sp); + + gen_set_sr(s, ccr, true); + tcg_temp_free(ccr); + + gen_jmp(s, tmp); +} + DISAS_INSN(rts) { TCGv tmp; @@ -6015,6 +6034,7 @@ void register_m68k_insns (CPUM68KState *env) BASE(nop, 4e71, ffff); INSN(rtd, 4e74, ffff, RTD); BASE(rts, 4e75, ffff); + INSN(rtr, 4e77, ffff, M68000); BASE(jump, 4e80, ffc0); BASE(jump, 4ec0, ffc0); INSN(addsubq, 5000, f080, M68000); -- cgit v1.1