diff --git a/nemu/src/isa/riscv32/inst.c b/nemu/src/isa/riscv32/inst.c
index 9224f10..1dd92ab 100644
--- a/nemu/src/isa/riscv32/inst.c
+++ b/nemu/src/isa/riscv32/inst.c
@@ -13,6 +13,7 @@
 * See the Mulan PSL v2 for more details.
 ***************************************************************************************/
 
+#include "common.h"
 #include "local-include/reg.h"
 #include <cpu/cpu.h>
 #include <cpu/ifetch.h>
@@ -23,7 +24,7 @@
 #define Mw vaddr_write
 
 enum {
-  TYPE_R, TYPE_I, TYPE_U, TYPE_S, TYPE_J,
+  TYPE_R, TYPE_I, TYPE_U, TYPE_S, TYPE_B, TYPE_J,
   TYPE_N, // none
 };
 
@@ -32,7 +33,8 @@ enum {
 #define immI() do { *imm = SEXT(BITS(i, 31, 20), 12); } while(0)
 #define immU() do { *imm = SEXT(BITS(i, 31, 12), 20) << 12; } while(0)
 #define immS() do { *imm = (SEXT(BITS(i, 31, 25), 7) << 5) | BITS(i, 11, 7); } while(0)
-#define immJ() do { *imm = (SEXT(BITS(i, 31, 30), 1) << 20) | BITS(i, 30, 21) << 1 | BITS(i, 21, 20) << 11 | BITS(i, 19, 12) << 12; } while(0)
+#define immB() do { *imm = (SEXT(BITS(i, 31, 31), 1) << 12 | BITS(i, 30, 25) << 5 | BITS(i, 11, 8) << 1 | BITS(i, 8, 8) << 11; } while(0)
+#define immJ() do { *imm = (SEXT(BITS(i, 31, 31), 1) << 20) | BITS(i, 30, 21) << 1 | BITS(i, 20, 20) << 11 | BITS(i, 19, 12) << 12; } while(0)
 
 static void decode_operand(Decode *s, int *rd, word_t *src1, word_t *src2, word_t *imm, int type) {
   uint32_t i = s->isa.inst.val;
@@ -48,6 +50,12 @@ static void decode_operand(Decode *s, int *rd, word_t *src1, word_t *src2, word_
   }
 }
 
+static void do_branch(Decode *s, bool condition, word_t offset) {
+  if (condition) {
+    s->dnpc = s->pc + offset;
+  }
+}
+
 static int decode_exec(Decode *s) {
   int rd = 0;
   word_t src1 = 0, src2 = 0, imm = 0;
@@ -64,10 +72,21 @@ static int decode_exec(Decode *s) {
   INSTPAT("??????? ????? ????? ??? ????? 00101 11", auipc  , U, R(rd) = s->pc + imm);
   INSTPAT("??????? ????? ????? ??? ????? 11011 11", jal    , J, do {s->dnpc = s->pc + imm; R(rd) = s->pc + 4; } while(0));
   INSTPAT("??????? ????? ????? ??? ????? 11001 11", jalr   , I, do {s->dnpc = src1 + imm; R(rd) = s->pc + 4; } while(0));
+  INSTPAT("??????? ????? ????? 000 ????? 11000 11", beq    , B, do_branch(s, src1 == src2, imm));
+  INSTPAT("??????? ????? ????? 001 ????? 11000 11", bne    , B, do_branch(s, src1 != src2, imm));
+  INSTPAT("??????? ????? ????? 100 ????? 11000 11", blt    , B, do_branch(s, (sword_t)src1 < (sword_t)src2, imm));
+  INSTPAT("??????? ????? ????? 101 ????? 11000 11", bge    , B, do_branch(s, (sword_t)src1 >= (sword_t)src2, imm));
+  INSTPAT("??????? ????? ????? 110 ????? 11000 11", bltu   , B, do_branch(s, src1 < src2, imm));
+  INSTPAT("??????? ????? ????? 111 ????? 11000 11", bgeu   , B, do_branch(s, src1 >= src2, imm));
+  INSTPAT("??????? ????? ????? 000 ????? 00000 11", lb     , I, R(rd) = SEXT(Mr(src1 + imm, 1), 8));
+  INSTPAT("??????? ????? ????? 001 ????? 00000 11", lh     , I, R(rd) = SEXT(Mr(src1 + imm, 2), 16));
+  INSTPAT("??????? ????? ????? 010 ????? 00000 11", lw     , I, R(rd) = SEXT(Mr(src1 + imm, 4), 32));
   INSTPAT("??????? ????? ????? 100 ????? 00000 11", lbu    , I, R(rd) = Mr(src1 + imm, 1));
+  INSTPAT("??????? ????? ????? 101 ????? 00000 11", lhu    , I, R(rd) = Mr(src1 + imm, 2));
   INSTPAT("??????? ????? ????? 000 ????? 01000 11", sb     , S, Mw(src1 + imm, 1, src2));
+  INSTPAT("??????? ????? ????? 001 ????? 01000 11", sh     , S, Mw(src1 + imm, 2, src2));
   INSTPAT("??????? ????? ????? 010 ????? 01000 11", sw     , S, Mw(src1 + imm, 4, src2));
-  INSTPAT("??????? ????? ????? 000 ????? 00100 11", addi   , I, R(rd) = src1 + (sword_t)imm);
+  INSTPAT("??????? ????? ????? 000 ????? 00100 11", addi   , I, R(rd) = src1 + imm);
   INSTPAT("0000000 ????? ????? 000 ????? 01100 11", add    , R, R(rd) = src1 + src2);
 
   INSTPAT("0000000 00001 00000 000 00000 11100 11", ebreak , N, NEMUTRAP(s->pc, R(10))); // R(10) is $a0