diff options
| -rw-r--r-- | subx/011direct_addressing.cc | 3 | ||||
| -rw-r--r-- | subx/012indirect_addressing.cc | 101 | ||||
| -rw-r--r-- | subx/013immediate_addressing.cc | 32 | ||||
| -rw-r--r-- | subx/014index_addressing.cc | 20 | ||||
| -rw-r--r-- | subx/017functions.cc | 8 |
5 files changed, 123 insertions, 41 deletions
diff --git a/subx/011direct_addressing.cc b/subx/011direct_addressing.cc index 66dbc43a..fffcbd6a 100644 --- a/subx/011direct_addressing.cc +++ b/subx/011direct_addressing.cc @@ -290,8 +290,11 @@ void push(uint32_t val) { :(scenario pop_r32) % Reg[ESP].u = 0x60; % write_mem_i32(0x60, 0x0000000a); +== 0x1 # code segment # op ModR/M SIB displacement immediate 5b # pop stack to EBX +== 0x60 # data segment +0a 00 00 00 # 0x0a +run: pop into EBX +run: popping value 0x0000000a +run: incrementing ESP to 0x00000064 diff --git a/subx/012indirect_addressing.cc b/subx/012indirect_addressing.cc index 59147c2d..df56a248 100644 --- a/subx/012indirect_addressing.cc +++ b/subx/012indirect_addressing.cc @@ -30,10 +30,12 @@ case 0: // indirect addressing :(scenario add_mem_at_r32_to_r32) % Reg[EAX].i = 0x60; % Reg[EBX].i = 0x10; -% write_mem_i32(0x60, 1); +== 0x01 # code segment # op ModR/M SIB displacement immediate 03 18 # add *EAX to EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add r/m32 to EBX +run: effective address is 0x60 (EAX) +run: storing 0x00000011 @@ -52,11 +54,13 @@ case 0x03: { // add r/m32 to r32 :(scenario subtract_r32_from_mem_at_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 10); % Reg[EBX].i = 1; +== 0x01 # code segment # op ModR/M SIB displacement immediate 29 18 # subtract EBX from *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0a 00 00 00 # 10 +run: subtract EBX from r/m32 +run: effective address is 0x60 (EAX) +run: storing 0x00000009 @@ -65,11 +69,13 @@ case 0x03: { // add r/m32 to r32 :(scenario subtract_mem_at_r32_from_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 1); % Reg[EBX].i = 10; +== 0x01 # code segment # op ModR/M SIB displacement immediate 2b 18 # subtract *EAX from EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: subtract r/m32 from EBX +run: effective address is 0x60 (EAX) +run: storing 0x00000009 @@ -88,11 +94,13 @@ case 0x2b: { // subtract r/m32 from r32 :(scenario and_r32_with_mem_at_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0xff; +== 0x01 # code segment # op ModR/M SIB displacement immediate 21 18 # and EBX with *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: and EBX with r/m32 +run: effective address is 0x60 (EAX) +run: storing 0x0000000d @@ -101,11 +109,13 @@ case 0x2b: { // subtract r/m32 from r32 :(scenario and_mem_at_r32_with_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x000000ff); % Reg[EBX].i = 0x0a0b0c0d; +== 0x01 # code segment # op ModR/M SIB displacement immediate 23 18 # and *EAX with EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +ff 00 00 00 # 0xff +run: and r/m32 with EBX +run: effective address is 0x60 (EAX) +run: storing 0x0000000d @@ -124,11 +134,13 @@ case 0x23: { // and r/m32 with r32 :(scenario or_r32_with_mem_at_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0xa0b0c0d0; +== 0x01 # code segment # op ModR/M SIB displacement immediate 09 18 # or EBX with *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: or EBX with r/m32 +run: effective address is 0x60 (EAX) +run: storing 0xaabbccdd @@ -137,11 +149,13 @@ case 0x23: { // and r/m32 with r32 :(scenario or_mem_at_r32_with_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0xa0b0c0d0; +== 0x01 # code segment # op ModR/M SIB displacement immediate 0b 18 # or *EAX with EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: or r/m32 with EBX +run: effective address is 0x60 (EAX) +run: storing 0xaabbccdd @@ -160,11 +174,13 @@ case 0x0b: { // or r/m32 with r32 :(scenario xor_r32_with_mem_at_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0xaabb0c0d); % Reg[EBX].i = 0xa0b0c0d0; +== 0x01 # code segment # op ModR/M SIB displacement immediate 31 18 # xor EBX with *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c bb aa # 0xaabb0c0d +run: xor EBX with r/m32 +run: effective address is 0x60 (EAX) +run: storing 0x0a0bccdd @@ -173,11 +189,13 @@ case 0x0b: { // or r/m32 with r32 :(scenario xor_mem_at_r32_with_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0xa0b0c0d0; +== 0x01 # code segment # op ModR/M SIB displacement immediate 33 18 # xor *EAX with EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: xor r/m32 with EBX +run: effective address is 0x60 (EAX) +run: storing 0xaabbccdd @@ -196,11 +214,12 @@ case 0x33: { // xor r/m32 with r32 :(scenario not_r32_with_mem_at_r32) % Reg[EBX].i = 0x60; -# word at 0x60 is 0x0f0f00ff -% write_mem_i32(0x60, 0x0f0f00ff); +== 0x01 # code segment # op ModR/M SIB displacement immediate f7 03 # negate *EBX # ModR/M in binary: 00 (indirect mode) 000 (unused) 011 (dest EBX) +== 0x60 # data segment +ff 00 0f 0f # 0x0f0f00ff +run: 'not' of r/m32 +run: effective address is 0x60 (EBX) +run: storing 0xf0f0ff00 @@ -209,33 +228,39 @@ case 0x33: { // xor r/m32 with r32 :(scenario compare_mem_at_r32_with_r32_greater) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0x0a0b0c07; +== 0x01 # code segment # op ModR/M SIB displacement immediate 39 18 # compare EBX with *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: compare EBX with r/m32 +run: effective address is 0x60 (EAX) +run: SF=0; ZF=0; OF=0 :(scenario compare_mem_at_r32_with_r32_lesser) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c07); % Reg[EBX].i = 0x0a0b0c0d; +== 0x01 # code segment # op ModR/M SIB displacement immediate 39 18 # compare EBX with *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +07 0c 0b 0a # 0x0a0b0c0d +run: compare EBX with r/m32 +run: effective address is 0x60 (EAX) +run: SF=1; ZF=0; OF=0 :(scenario compare_mem_at_r32_with_r32_equal) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0x0a0b0c0d; +== 0x01 # code segment # op ModR/M SIB displacement immediate 39 18 # compare EBX with *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: compare EBX with r/m32 +run: effective address is 0x60 (EAX) +run: SF=0; ZF=1; OF=0 @@ -244,11 +269,13 @@ case 0x33: { // xor r/m32 with r32 :(scenario compare_r32_with_mem_at_r32_greater) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c07); % Reg[EBX].i = 0x0a0b0c0d; +== 0x01 # code segment # op ModR/M SIB displacement immediate 3b 18 # compare *EAX with EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +07 0c 0b 0a # 0x0a0b0c0d +run: compare r/m32 with EBX +run: effective address is 0x60 (EAX) +run: SF=0; ZF=0; OF=0 @@ -271,22 +298,26 @@ case 0x3b: { // set SF if r32 < r/m32 :(scenario compare_r32_with_mem_at_r32_lesser) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0x0a0b0c07; +== 0x01 # code segment # op ModR/M SIB displacement immediate 3b 18 # compare *EAX with EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: compare r/m32 with EBX +run: effective address is 0x60 (EAX) +run: SF=1; ZF=0; OF=0 :(scenario compare_r32_with_mem_at_r32_equal) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x0a0b0c0d); % Reg[EBX].i = 0x0a0b0c0d; +== 0x01 # code segment # op ModR/M SIB displacement immediate 3b 18 # compare *EAX with EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +0d 0c 0b 0a # 0x0a0b0c0d +run: compare r/m32 with EBX +run: effective address is 0x60 (EAX) +run: SF=0; ZF=1; OF=0 @@ -307,10 +338,12 @@ case 0x3b: { // set SF if r32 < r/m32 :(scenario copy_mem_at_r32_to_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x000000af); +== 0x01 # code segment # op ModR/M SIB displacement immediate 8b 18 # copy *EAX to EBX # ModR/M in binary: 00 (indirect mode) 011 (src EAX) 000 (dest EAX) +== 0x60 # data segment +af 00 00 00 # 0xaf +run: copy r/m32 to EBX +run: effective address is 0x60 (EAX) +run: storing 0x000000af @@ -330,12 +363,14 @@ case 0x8b: { // copy r32 to r/m32 :(scenario jump_mem_at_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 8); +== 0x01 # code segment # op ModR/M SIB displacement immediate ff 20 # jump to *EAX # ModR/M in binary: 00 (indirect mode) 100 (jump to r/m32) 000 (src EAX) 05 00 00 00 01 05 00 00 00 02 +== 0x60 # data segment +08 00 00 00 # 8 +run: inst: 0x00000001 +run: jump to r/m32 +run: effective address is 0x60 (EAX) @@ -364,11 +399,13 @@ case 0xff: { :(scenario push_mem_at_r32) % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 0x000000af); % Reg[ESP].u = 0x14; +== 0x01 # code segment # op ModR/M SIB displacement immediate ff 30 # push *EAX to stack # ModR/M in binary: 00 (indirect mode) 110 (push r/m32) 000 (src EAX) +== 0x60 # data segment +af 00 00 00 # 0xaf +run: push r/m32 +run: effective address is 0x60 (EAX) +run: decrementing ESP to 0x00000010 @@ -387,10 +424,12 @@ case 6: { // push r/m32 to stack :(scenario pop_mem_at_r32) % Reg[EAX].i = 0x60; % Reg[ESP].u = 0x10; -% write_mem_i32(0x10, 0x00000030); +== 0x01 # code segment # op ModR/M SIB displacement immediate 8f 00 # pop stack into *EAX # ModR/M in binary: 00 (indirect mode) 000 (pop r/m32) 000 (dest EAX) +== 0x10 # data segment +30 00 00 00 # 0x30 +run: pop into r/m32 +run: effective address is 0x60 (EAX) +run: popping value 0x00000030 @@ -415,10 +454,12 @@ case 0x8f: { // pop stack into r/m32 :(scenario add_r32_to_mem_at_displacement) % Reg[EBX].i = 0x10; // source -% write_mem_i32(0x60, 1); +== 0x01 # code segment # op ModR/M SIB displacement immediate 01 1d 60 00 00 00 # add EBX to *0x60 # ModR/M in binary: 00 (indirect mode) 011 (src EBX) 101 (dest in disp32) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is 0x60 (disp32) +run: storing 0x00000011 @@ -434,10 +475,12 @@ case 5: // exception: mod 0b00 rm 0b101 => incoming disp32 :(scenario add_r32_to_mem_at_r32_plus_disp8) % Reg[EBX].i = 0x10; // source % Reg[EAX].i = 0x5e; // dest -% write_mem_i32(0x60, 1); +== 0x01 # code segment # op ModR/M SIB displacement immediate 01 58 02 # add EBX to *(EAX+2) # ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 000 (dest EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x5e (EAX) +run: effective address is 0x60 (after adding disp8) @@ -461,10 +504,12 @@ case 1: // indirect + disp8 addressing :(scenario add_r32_to_mem_at_r32_plus_negative_disp8) % Reg[EBX].i = 0x10; // source % Reg[EAX].i = 0x61; // dest -% write_mem_i32(0x60, 1); +== 0x01 # code segment # op ModR/M SIB displacement immediate 01 58 ff # add EBX to *(EAX-1) # ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 000 (dest EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x61 (EAX) +run: effective address is 0x60 (after adding disp8) @@ -475,10 +520,12 @@ case 1: // indirect + disp8 addressing :(scenario add_r32_to_mem_at_r32_plus_disp32) % Reg[EBX].i = 0x10; // source % Reg[EAX].i = 0x5e; // dest -% write_mem_i32(0x60, 1); +== 0x01 # code segment # op ModR/M SIB displacement immediate 01 98 02 00 00 00 # add EBX to *(EAX+2) # ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 000 (dest EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x5e (EAX) +run: effective address is 0x60 (after adding disp32) @@ -502,10 +549,12 @@ case 2: // indirect + disp32 addressing :(scenario add_r32_to_mem_at_r32_plus_negative_disp32) % Reg[EBX].i = 0x10; // source % Reg[EAX].i = 0x61; // dest -% write_mem_i32(0x60, 1); +== 0x01 # code segment # op ModR/M SIB displacement immediate 01 98 ff ff ff ff # add EBX to *(EAX-1) # ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 000 (dest EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x61 (EAX) +run: effective address is 0x60 (after adding disp32) diff --git a/subx/013immediate_addressing.cc b/subx/013immediate_addressing.cc index ceb998ef..c1e88f21 100644 --- a/subx/013immediate_addressing.cc +++ b/subx/013immediate_addressing.cc @@ -34,10 +34,12 @@ case 0x81: { // combine imm32 with r/m32 :(scenario add_imm32_to_mem_at_r32) % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 1); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 03 0a 0b 0c 0d # add 0x0d0c0b0a to *EBX # ModR/M in binary: 00 (indirect mode) 000 (add imm32) 011 (dest EBX) +== 0x60 # data segment +01 00 00 00 # 1 +run: combine imm32 0x0d0c0b0a with r/m32 +run: effective address is 0x60 (EBX) +run: subop add @@ -64,10 +66,12 @@ case 0x2d: { // subtract imm32 from EAX :(scenario subtract_imm32_from_mem_at_r32) % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 10); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 2b 01 00 00 00 # subtract 1 from *EBX # ModR/M in binary: 00 (indirect mode) 101 (subtract imm32) 011 (dest EBX) +== 0x60 # data segment +0a 00 00 00 # 10 +run: combine imm32 0x00000001 with r/m32 +run: effective address is 0x60 (EBX) +run: subop subtract @@ -113,10 +117,12 @@ case 0x25: { // and imm32 with EAX :(scenario and_imm32_with_mem_at_r32) % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 0x000000ff); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 23 0a 0b 0c 0d # and 0x0d0c0b0a with *EBX # ModR/M in binary: 00 (indirect mode) 100 (and imm32) 011 (dest EBX) +== 0x60 # data segment +ff 00 00 00 # 0xff +run: combine imm32 0x0d0c0b0a with r/m32 +run: effective address is 0x60 (EBX) +run: subop and @@ -162,10 +168,12 @@ case 0x0d: { // or imm32 with EAX :(scenario or_imm32_with_mem_at_r32) % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 0xd0c0b0a0); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 0b 0a 0b 0c 0d # or 0x0d0c0b0a with *EBX # ModR/M in binary: 00 (indirect mode) 001 (or imm32) 011 (dest EBX) +== 0x60 # data segment +a0 b0 c0 d0 # 0xd0c0b0a0 +run: combine imm32 0x0d0c0b0a with r/m32 +run: effective address is 0x60 (EBX) +run: subop or @@ -209,10 +217,12 @@ case 0x35: { // xor imm32 with EAX :(scenario xor_imm32_with_mem_at_r32) % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 0xd0c0b0a0); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 33 0a 0b 0c 0d # xor 0x0d0c0b0a with *EBX # ModR/M in binary: 00 (indirect mode) 110 (xor imm32) 011 (dest EBX) +== 0x60 # data segment +a0 b0 c0 d0 # 0xd0c0b0a0 +run: combine imm32 0x0d0c0b0a with r/m32 +run: effective address is 0x60 (EBX) +run: subop xor @@ -315,20 +325,24 @@ case 7: { :(scenario compare_imm32_with_mem_at_r32_greater) % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 0x0d0c0b0a); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 3b 07 0b 0c 0d # compare 0x0d0c0b07 with *EBX # ModR/M in binary: 00 (indirect mode) 111 (compare imm32) 011 (dest EBX) +== 0x60 # data segment +0a 0b 0c 0d # 0x0d0c0b0a +run: combine imm32 0x0d0c0b07 with r/m32 +run: effective address is 0x60 (EBX) +run: SF=0; ZF=0; OF=0 :(scenario compare_imm32_with_mem_at_r32_lesser) % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 0x0d0c0b07); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 3b 0a 0b 0c 0d # compare 0x0d0c0b0a with *EBX # ModR/M in binary: 00 (indirect mode) 111 (compare imm32) 011 (dest EBX) +== 0x60 # data segment +07 0b 0c 0d # 0x0d0c0b07 +run: combine imm32 0x0d0c0b0a with r/m32 +run: effective address is 0x60 (EBX) +run: SF=1; ZF=0; OF=0 @@ -336,10 +350,12 @@ case 7: { :(scenario compare_imm32_with_mem_at_r32_equal) % Reg[EBX].i = 0x0d0c0b0a; % Reg[EBX].i = 0x60; -% write_mem_i32(0x60, 0x0d0c0b0a); +== 0x01 # code segment # op ModR/M SIB displacement immediate 81 3b 0a 0b 0c 0d # compare 0x0d0c0b0a with *EBX # ModR/M in binary: 00 (indirect mode) 111 (compare imm32) 011 (dest EBX) +== 0x60 # data segment +0a 0b 0c 0d # 0x0d0c0b0a +run: combine imm32 0x0d0c0b0a with r/m32 +run: effective address is 0x60 (EBX) +run: SF=0; ZF=1; OF=0 diff --git a/subx/014index_addressing.cc b/subx/014index_addressing.cc index fe80de13..13287709 100644 --- a/subx/014index_addressing.cc +++ b/subx/014index_addressing.cc @@ -3,11 +3,13 @@ :(scenario add_r32_to_mem_at_r32_with_sib) % Reg[EBX].i = 0x10; % Reg[EAX].i = 0x60; -% write_mem_i32(0x60, 1); +== 0x1 # code segment # op ModR/M SIB displacement immediate 01 1c 20 # add EBX to *EAX # ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB) # SIB in binary: 00 (scale 1) 100 (no index) 000 (base EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x60 (EAX) +run: effective address is 0x60 @@ -48,11 +50,13 @@ uint32_t effective_address_from_sib(uint8_t mod) { % Reg[EBX].i = 0x10; // source % Reg[EAX].i = 0x5e; // dest base % Reg[ECX].i = 0x2; // dest index -% write_mem_i32(0x60, 1); +== 0x1 # code segment # op ModR/M SIB displacement immediate 01 1c 08 # add EBX to *(EAX+ECX) # ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB) # SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x5e (EAX) +run: effective address is 0x60 (after adding ECX*1) @@ -60,11 +64,13 @@ uint32_t effective_address_from_sib(uint8_t mod) { :(scenario add_r32_to_mem_at_displacement_using_sib) % Reg[EBX].i = 0x10; // source -% write_mem_i32(0x60, 1); +== 0x1 # code segment # op ModR/M SIB displacement immediate 01 1c 25 60 00 00 00 # add EBX to *0x60 # ModR/M in binary: 00 (indirect mode) 011 (src EBX) 100 (dest in SIB) # SIB in binary: 00 (scale 1) 100 (no index) 101 (not EBP but disp32) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x60 (disp32) +run: effective address is 0x60 @@ -76,11 +82,13 @@ uint32_t effective_address_from_sib(uint8_t mod) { % Reg[EBX].i = 0x10; // source % Reg[EAX].i = 0x59; // dest base % Reg[ECX].i = 0x5; // dest index -% write_mem_i32(0x60, 1); +== 0x1 # code segment # op ModR/M SIB displacement immediate 01 5c 08 02 # add EBX to *(EAX+ECX+2) # ModR/M in binary: 01 (indirect+disp8 mode) 011 (src EBX) 100 (dest in SIB) # SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x59 (EAX) +run: effective address is 0x5e (after adding ECX*1) @@ -98,11 +106,13 @@ case 4: // exception: mod 0b01 rm 0b100 => incoming SIB (scale-index-base) byte % Reg[EBX].i = 0x10; // source % Reg[EAX].i = 0x59; // dest base % Reg[ECX].i = 0x5; // dest index -% write_mem_i32(0x60, 1); +== 0x1 # code segment # op ModR/M SIB displacement immediate 01 9c 08 02 00 00 00 # add EBX to *(EAX+ECX+2) # ModR/M in binary: 10 (indirect+disp32 mode) 011 (src EBX) 100 (dest in SIB) # SIB in binary: 00 (scale 1) 001 (index ECX) 000 (base EAX) +== 0x60 # data segment +01 00 00 00 # 1 +run: add EBX to r/m32 +run: effective address is initially 0x59 (EAX) +run: effective address is 0x5e (after adding ECX*1) diff --git a/subx/017functions.cc b/subx/017functions.cc index 13ac41d9..163894f2 100644 --- a/subx/017functions.cc +++ b/subx/017functions.cc @@ -47,10 +47,12 @@ case 2: { // call function pointer at r/m32 :(scenario call_mem_at_r32) % Reg[ESP].u = 0x64; % Reg[EBX].u = 0x10; -% write_mem_i32(0x10, 0x000000a0); +== 0x1 # code segment # op ModR/M SIB displacement immediate ff 13 # call function offset at *EBX # next EIP is 3 +== 0x10 # data segment +a0 00 00 00 # 0xa0 +run: call to r/m32 +run: effective address is 0x10 (EBX) +run: decrementing ESP to 0x00000060 @@ -61,9 +63,11 @@ case 2: { // call function pointer at r/m32 :(scenario ret) % Reg[ESP].u = 0x60; -% write_mem_i32(0x60, 0x00000010); +== 0x1 # code segment # op ModR/M SIB displacement immediate c3 +== 0x60 # data segment +10 00 00 00 # 0x10 +run: return +run: popping value 0x00000010 +run: jumping to 0x00000010 |