diff --git a/cpu/ppc/ppcemu.h b/cpu/ppc/ppcemu.h
index 74b46cc..c25b7ee 100644
--- a/cpu/ppc/ppcemu.h
+++ b/cpu/ppc/ppcemu.h
@@ -196,14 +196,12 @@ extern uint64_t ppc_result64_b;
 extern uint64_t ppc_result64_c;
 extern uint64_t ppc_result64_d;
 
-
-/* The precise end of a basic block. */
-enum class BB_end_kind {
-    BB_NONE   = 0, /* no basic block end is reached       */
-    BB_BRANCH = 1, /* a branch instruction is encountered */
-    BB_EXCEPTION,  /* an exception is occured             */
-    BB_RFI,        /* the rfi instruction is encountered  */
-    BB_TIMER,      /* timer queue changed                 */
+/* Flags for controlling interpreter execution. */
+enum {
+    EXEF_BRANCH    = 1 << 0,
+    EXEF_EXCEPTION = 1 << 1,
+    EXEF_RFI       = 1 << 2,
+    EXEF_TIMER     = 1 << 7
 };
 
 enum CR_select : int32_t {
@@ -293,8 +291,7 @@ enum Exc_Cause : uint32_t {
     TRAP        = 1 << (31 - 14),
 };
 
-// extern bool bb_end;
-extern BB_end_kind bb_kind;
+extern unsigned exec_flags;
 
 extern jmp_buf exc_env;
 
diff --git a/cpu/ppc/ppcexceptions.cpp b/cpu/ppc/ppcexceptions.cpp
index 24a1a4e..17825e3 100644
--- a/cpu/ppc/ppcexceptions.cpp
+++ b/cpu/ppc/ppcexceptions.cpp
@@ -21,8 +21,10 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 /** @file Handling of low-level PPC exceptions. */
 
+#include <loguru.hpp>
 #include "ppcemu.h"
 #include "ppcmmu.h"
+
 #include <setjmp.h>
 #include <stdexcept>
 #include <string>
@@ -59,7 +61,7 @@ void ppc_exception_handler(Except_Type exception_type, uint32_t srr1_bits) {
         break;
 
     case Except_Type::EXC_EXT_INT:
-        if (bb_kind != BB_end_kind::BB_NONE) {
+        if (exec_flags & ~EXEF_TIMER) {
             ppc_state.spr[SPR::SRR0] = ppc_next_instruction_address;
         } else {
             ppc_state.spr[SPR::SRR0] = (ppc_state.pc & 0xFFFFFFFCUL) + 4;
@@ -98,8 +100,7 @@ void ppc_exception_handler(Except_Type exception_type, uint32_t srr1_bits) {
         break;
 
     default:
-        // printf("Unknown exception occured: %X\n", exception_type);
-        // exit(-1);
+        ABORT_F("Unknown exception occured: %X\n", exception_type);
         break;
     }
 
@@ -112,7 +113,7 @@ void ppc_exception_handler(Except_Type exception_type, uint32_t srr1_bits) {
         ppc_next_instruction_address |= 0xFFF00000;
     }
 
-    bb_kind = BB_end_kind::BB_EXCEPTION;
+    exec_flags = EXEF_EXCEPTION;
 
     // perform context synchronization for recoverable exceptions
     if (exception_type != Except_Type::EXC_MACHINE_CHECK &&
diff --git a/cpu/ppc/ppcexec.cpp b/cpu/ppc/ppcexec.cpp
index a530304..afdbe09 100644
--- a/cpu/ppc/ppcexec.cpp
+++ b/cpu/ppc/ppcexec.cpp
@@ -55,7 +55,7 @@ uint32_t ppc_cur_instruction;    // Current instruction for the PPC
 uint32_t ppc_effective_address;
 uint32_t ppc_next_instruction_address;    // Used for branching, setting up the NIA
 
-BB_end_kind bb_kind; /* basic block end */
+unsigned exec_flags;
 
 /* copy of local variable bb_start_la. Need for correct
    calculation of CPU cycles after setjmp that clobbers
@@ -319,11 +319,7 @@ uint64_t process_events()
 void force_cycle_counter_reload()
 {
     // tell the interpreter loop to reload cycle counter
-    if (bb_kind == BB_end_kind::BB_NONE || bb_kind == BB_end_kind::BB_TIMER) {
-        bb_kind = BB_end_kind::BB_TIMER;
-    } else {
-        ABORT_F("PPCEXEC: attempt to override basic block type %d", bb_kind);
-    }
+    exec_flags |= EXEF_TIMER;
 }
 
 /** Execute PPC code as long as power is on. */
@@ -401,10 +397,9 @@ static void ppc_exec_inner()
     while (power_on) {
         // define boundaries of the next execution block
         // max execution block length = one memory page
-        eb_start = ppc_state.pc;
-        eb_end   = (eb_start + PAGE_SIZE) & PAGE_MASK;
-        //eb_last = false;
-        bb_kind  = BB_end_kind::BB_NONE;
+        eb_start   = ppc_state.pc;
+        eb_end     = (eb_start + PAGE_SIZE) & PAGE_MASK;
+        exec_flags = 0;
 
         page_start = eb_start & PAGE_MASK;
         pc_real    = mmu_translate_imem(eb_start);
@@ -416,17 +411,19 @@ static void ppc_exec_inner()
                 max_cycles = process_events();
             }
 
-            if (bb_kind != BB_end_kind::BB_NONE) { // execution block ended ?
+            if (exec_flags) {
                 if (!power_on)
                     break;
                 // reload cycle counter if requested
-                if (bb_kind == BB_end_kind::BB_TIMER) {
+                if (exec_flags & EXEF_TIMER) {
                     max_cycles = process_events();
-                    ppc_state.pc += 4;
-                    pc_real += 4;
-                    ppc_set_cur_instruction(pc_real);
-                    bb_kind = BB_end_kind::BB_NONE;
-                    continue;
+                    if (!(exec_flags & ~EXEF_TIMER)) {
+                        ppc_state.pc += 4;
+                        pc_real += 4;
+                        ppc_set_cur_instruction(pc_real);
+                        exec_flags = 0;
+                        continue;
+                    }
                 }
                 // define next execution block
                 eb_start = ppc_next_instruction_address;
@@ -439,7 +436,7 @@ static void ppc_exec_inner()
                     pc_real = mmu_translate_imem(eb_start);
                 }
                 ppc_state.pc = eb_start;
-                bb_kind = BB_end_kind::BB_NONE;
+                exec_flags = 0;
             } else {
                 ppc_state.pc += 4;
                 pc_real += 4;
@@ -506,19 +503,19 @@ void ppc_exec_single()
         // process low-level exceptions
         //LOG_F(9, "PPC-EXEC: low_level exception raised!");
         ppc_state.pc = ppc_next_instruction_address;
-        bb_kind = BB_end_kind::BB_NONE;
+        exec_flags = 0;
         return;
     }
 
     mmu_translate_imem(ppc_state.pc);
     ppc_main_opcode();
-    if (bb_kind != BB_end_kind::BB_NONE) {
-        if (bb_kind == BB_end_kind::BB_TIMER) {
+    if (exec_flags) {
+        if (exec_flags & EXEF_TIMER) {
             ppc_state.pc += 4;
         } else {
             ppc_state.pc = ppc_next_instruction_address;
         }
-        bb_kind = BB_end_kind::BB_NONE;
+        exec_flags = 0;
     } else {
         ppc_state.pc += 4;
     }
@@ -599,10 +596,9 @@ static void ppc_exec_until_inner(const uint32_t goal_addr)
     while (ppc_state.pc != goal_addr) {
         // define boundaries of the next execution block
         // max execution block length = one memory page
-        eb_start = ppc_state.pc;
-        eb_end   = (eb_start + PAGE_SIZE) & PAGE_MASK;
-        //eb_last = false;
-        bb_kind  = BB_end_kind::BB_NONE;
+        eb_start   = ppc_state.pc;
+        eb_end     = (eb_start + PAGE_SIZE) & PAGE_MASK;
+        exec_flags = 0;
 
         page_start = eb_start & PAGE_MASK;
         pc_real    = mmu_translate_imem(eb_start);
@@ -614,15 +610,17 @@ static void ppc_exec_until_inner(const uint32_t goal_addr)
                 max_cycles = process_events();
             }
 
-            if (bb_kind != BB_end_kind::BB_NONE) { // execution block ended ?
+            if (exec_flags) {
                 // reload cycle counter if requested
-                if (bb_kind == BB_end_kind::BB_TIMER) {
+                if (exec_flags & EXEF_TIMER) {
                     max_cycles = process_events();
-                    ppc_state.pc += 4;
-                    pc_real += 4;
-                    ppc_set_cur_instruction(pc_real);
-                    bb_kind = BB_end_kind::BB_NONE;
-                    continue;
+                    if (!(exec_flags & ~EXEF_TIMER)) {
+                        ppc_state.pc += 4;
+                        pc_real += 4;
+                        ppc_set_cur_instruction(pc_real);
+                        exec_flags = 0;
+                        continue;
+                    }
                 }
                 // define next execution block
                 eb_start = ppc_next_instruction_address;
@@ -635,7 +633,7 @@ static void ppc_exec_until_inner(const uint32_t goal_addr)
                     pc_real = mmu_translate_imem(eb_start);
                 }
                 ppc_state.pc = eb_start;
-                bb_kind = BB_end_kind::BB_NONE;
+                exec_flags = 0;
             } else {
                 ppc_state.pc += 4;
                 pc_real += 4;
@@ -737,10 +735,9 @@ static void ppc_exec_dbg_inner(const uint32_t start_addr, const uint32_t size)
     while (ppc_state.pc < start_addr || ppc_state.pc >= start_addr + size) {
         // define boundaries of the next execution block
         // max execution block length = one memory page
-        eb_start = ppc_state.pc;
-        eb_end   = (eb_start + PAGE_SIZE) & PAGE_MASK;
-        //eb_last = false;
-        bb_kind  = BB_end_kind::BB_NONE;
+        eb_start   = ppc_state.pc;
+        eb_end     = (eb_start + PAGE_SIZE) & PAGE_MASK;
+        exec_flags = 0;
 
         page_start = eb_start & PAGE_MASK;
         pc_real    = mmu_translate_imem(eb_start);
@@ -753,16 +750,17 @@ static void ppc_exec_dbg_inner(const uint32_t start_addr, const uint32_t size)
                 max_cycles = process_events();
             }
 
-            //if (eb_last) {
-            if (bb_kind != BB_end_kind::BB_NONE) { // execution block ended ?
+            if (exec_flags) {
                 // reload cycle counter if requested
-                if (bb_kind == BB_end_kind::BB_TIMER) {
+                if (exec_flags & EXEF_TIMER) {
                     max_cycles = process_events();
-                    ppc_state.pc += 4;
-                    pc_real += 4;
-                    ppc_set_cur_instruction(pc_real);
-                    bb_kind = BB_end_kind::BB_NONE;
-                    continue;
+                    if (!(exec_flags & ~EXEF_TIMER)) {
+                        ppc_state.pc += 4;
+                        pc_real += 4;
+                        ppc_set_cur_instruction(pc_real);
+                        exec_flags = 0;
+                        continue;
+                    }
                 }
                 // define next execution block
                 eb_start = ppc_next_instruction_address;
@@ -775,7 +773,7 @@ static void ppc_exec_dbg_inner(const uint32_t start_addr, const uint32_t size)
                     pc_real = mmu_translate_imem(eb_start);
                 }
                 ppc_state.pc = eb_start;
-                bb_kind = BB_end_kind::BB_NONE;
+                exec_flags = 0;
             } else {
                 ppc_state.pc += 4;
                 pc_real += 4;
@@ -1039,6 +1037,8 @@ void ppc_cpu_init(MemCtrlBase* mem_ctrl, uint32_t cpu_version) {
     tbr_wr_value = 0;
     tbr_freq_hz = 16705000; // FIXME: this should be set properly during machine initialization
 
+    exec_flags = 0;
+
     timebase_counter = 0;
     decr = 0;
     old_decr_msb = decr >> 31;
diff --git a/cpu/ppc/ppcopcodes.cpp b/cpu/ppc/ppcopcodes.cpp
index 49babae..c79d3e2 100644
--- a/cpu/ppc/ppcopcodes.cpp
+++ b/cpu/ppc/ppcopcodes.cpp
@@ -995,7 +995,7 @@ void dppc_interpreter::ppc_b() {
     uint32_t quick_test = (ppc_cur_instruction & 0x03FFFFFC);
     adr_li              = (quick_test < 0x2000000) ? quick_test : (0xFC000000UL + quick_test);
     ppc_next_instruction_address = (uint32_t)(ppc_state.pc + adr_li);
-    bb_kind                      = BB_end_kind::BB_BRANCH;
+    exec_flags = EXEF_BRANCH;
 }
 
 void dppc_interpreter::ppc_bl() {
@@ -1003,14 +1003,14 @@ void dppc_interpreter::ppc_bl() {
     adr_li              = (quick_test < 0x2000000) ? quick_test : (0xFC000000UL + quick_test);
     ppc_next_instruction_address = (uint32_t)(ppc_state.pc + adr_li);
     ppc_state.spr[SPR::LR]       = (uint32_t)(ppc_state.pc + 4);
-    bb_kind                      = BB_end_kind::BB_BRANCH;
+    exec_flags = EXEF_BRANCH;
 }
 
 void dppc_interpreter::ppc_ba() {
     uint32_t quick_test = (ppc_cur_instruction & 0x03FFFFFC);
     adr_li              = (quick_test < 0x2000000) ? quick_test : (0xFC000000UL + quick_test);
     ppc_next_instruction_address = adr_li;
-    bb_kind                      = BB_end_kind::BB_BRANCH;
+    exec_flags = EXEF_BRANCH;
 }
 
 void dppc_interpreter::ppc_bla() {
@@ -1018,7 +1018,7 @@ void dppc_interpreter::ppc_bla() {
     adr_li              = (quick_test < 0x2000000) ? quick_test : (0xFC000000UL + quick_test);
     ppc_next_instruction_address = adr_li;
     ppc_state.spr[SPR::LR]       = ppc_state.pc + 4;
-    bb_kind                      = BB_end_kind::BB_BRANCH;
+    exec_flags = EXEF_BRANCH;
 }
 
 void dppc_interpreter::ppc_bc() {
@@ -1036,7 +1036,7 @@ void dppc_interpreter::ppc_bc() {
 
     if (ctr_ok && cnd_ok) {
         ppc_next_instruction_address = (ppc_state.pc + br_bd);
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
 }
 
@@ -1055,7 +1055,7 @@ void dppc_interpreter::ppc_bca() {
 
     if (ctr_ok && cnd_ok) {
         ppc_next_instruction_address = br_bd;
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
 }
 
@@ -1074,7 +1074,7 @@ void dppc_interpreter::ppc_bcl() {
 
     if (ctr_ok && cnd_ok) {
         ppc_next_instruction_address = (ppc_state.pc + br_bd);
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
     ppc_state.spr[SPR::LR] = ppc_state.pc + 4;
 }
@@ -1094,7 +1094,7 @@ void dppc_interpreter::ppc_bcla() {
 
     if (ctr_ok && cnd_ok) {
         ppc_next_instruction_address = br_bd;
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
     ppc_state.spr[SPR::LR] = ppc_state.pc + 4;
 }
@@ -1108,7 +1108,7 @@ void dppc_interpreter::ppc_bcctr() {
 
     if (cnd_ok) {
         ppc_next_instruction_address = (ppc_state.spr[SPR::CTR] & 0xFFFFFFFCUL);
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
 }
 
@@ -1121,7 +1121,7 @@ void dppc_interpreter::ppc_bcctrl() {
 
     if (cnd_ok) {
         ppc_next_instruction_address = (ppc_state.spr[SPR::CTR] & 0xFFFFFFFCUL);
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
     ppc_state.spr[SPR::LR] = ppc_state.pc + 4;
 }
@@ -1140,7 +1140,7 @@ void dppc_interpreter::ppc_bclr() {
 
     if (ctr_ok && cnd_ok) {
         ppc_next_instruction_address = (ppc_state.spr[SPR::LR] & 0xFFFFFFFCUL);
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
 }
 
@@ -1158,7 +1158,7 @@ void dppc_interpreter::ppc_bclrl() {
 
     if (ctr_ok && cnd_ok) {
         ppc_next_instruction_address = (ppc_state.spr[SPR::LR] & 0xFFFFFFFCUL);
-        bb_kind                      = BB_end_kind::BB_BRANCH;
+        exec_flags = EXEF_BRANCH;
     }
     ppc_state.spr[SPR::LR] = ppc_state.pc + 4;
 }
@@ -1332,7 +1332,7 @@ void dppc_interpreter::ppc_rfi() {
     mmu_change_mode();
 
     grab_return = true;
-    bb_kind     = BB_end_kind::BB_RFI;
+    exec_flags = EXEF_RFI;
 }
 
 void dppc_interpreter::ppc_sc() {