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authorLucien Murray-Pitts <lucienmp.qemu@gmail.com>2021-02-01 01:01:52 +0100
committerLaurent Vivier <laurent@vivier.eu>2021-02-11 21:10:01 +0100
commit7525a9b94c0c5733b8450c9451ca1de334f71ed8 (patch)
treeda772c2697bc26e425178014a12286b70a1739c8
parent8df0e6aedad33c6746f4bc2a4d0cfdd432877084 (diff)
downloadqemu-arm-7525a9b94c0c5733b8450c9451ca1de334f71ed8.tar.gz
m68k: add MSP detection support for stack pointer swap helpers
On m68k there are two varities of stack pointers: USP with SSP or ISP/MSP. Only the 68020/30/40 support the MSP register the stack swap helpers don't support this feature. This patch adds this support, as well as comments to CPUM68KState to make it clear how stacks are handled Signed-off-by: Lucien Murray-Pitts <lucienmp.qemu@gmail.com> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu> Message-Id: <c61ad2d8b39f3b03b431819b6bf602a1c332b921.1612137712.git.balaton@eik.bme.hu> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
-rw-r--r--target/m68k/cpu.c1
-rw-r--r--target/m68k/cpu.h9
-rw-r--r--target/m68k/helper.c3
3 files changed, 11 insertions, 2 deletions
diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
index ff3c4c1c98..37d2ed9dc7 100644
--- a/target/m68k/cpu.c
+++ b/target/m68k/cpu.c
@@ -160,6 +160,7 @@ static void m68020_cpu_initfn(Object *obj)
m68k_set_feature(env, M68K_FEATURE_FPU);
m68k_set_feature(env, M68K_FEATURE_CAS);
m68k_set_feature(env, M68K_FEATURE_CHK2);
+ m68k_set_feature(env, M68K_FEATURE_MSP);
}
/*
diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
index 5d2cb012e5..7c3feeaf8a 100644
--- a/target/m68k/cpu.h
+++ b/target/m68k/cpu.h
@@ -85,7 +85,13 @@ typedef struct CPUM68KState {
uint32_t pc;
uint32_t sr;
- /* SSP and USP. The current_sp is stored in aregs[7], the other here. */
+ /*
+ * The 68020/30/40 support two supervisor stacks, ISP and MSP.
+ * The 68000/10, Coldfire, and CPU32 only have USP/SSP.
+ *
+ * The current_sp is stored in aregs[7], the other here.
+ * The USP, SSP, and if used the additional ISP for 68020/30/40.
+ */
int current_sp;
uint32_t sp[3];
@@ -484,6 +490,7 @@ enum m68k_features {
M68K_FEATURE_CF_EMAC,
M68K_FEATURE_CF_EMAC_B, /* Revision B EMAC (dual accumulate). */
M68K_FEATURE_USP, /* User Stack Pointer. (680[012346]0, ISA A+, B or C).*/
+ M68K_FEATURE_MSP, /* Master Stack Pointer. (680[234]0) */
M68K_FEATURE_EXT_FULL, /* 68020+ full extension word. */
M68K_FEATURE_WORD_INDEX, /* word sized address index registers. */
M68K_FEATURE_SCALED_INDEX, /* scaled address index registers. */
diff --git a/target/m68k/helper.c b/target/m68k/helper.c
index 1efd6e4f65..4185ca94ce 100644
--- a/target/m68k/helper.c
+++ b/target/m68k/helper.c
@@ -463,7 +463,8 @@ void m68k_switch_sp(CPUM68KState *env)
env->sp[env->current_sp] = env->aregs[7];
if (m68k_feature(env, M68K_FEATURE_M68000)) {
if (env->sr & SR_S) {
- if (env->sr & SR_M) {
+ /* SR:Master-Mode bit unimplemented then ISP is not available */
+ if (!m68k_feature(env, M68K_FEATURE_MSP) || env->sr & SR_M) {
new_sp = M68K_SSP;
} else {
new_sp = M68K_ISP;