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| author | Kartik Agaram <vc@akkartik.com> | 2018-07-10 22:38:28 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2018-07-10 22:38:28 -0700 |
| commit | 39c0d1b1d55dd4ed478433427119f4ea11f7dcf0 (patch) | |
| tree | de489aa379842be24b49a480270154e91ef7780a /subx/014index_addressing.cc | |
| parent | c8c5065869d7500ab8ad80b135bb7b31262e597f (diff) | |
| download | mu-39c0d1b1d55dd4ed478433427119f4ea11f7dcf0.tar.gz | |
4340
Start using data segments in scenarios.
Diffstat (limited to 'subx/014index_addressing.cc')
| -rw-r--r-- | subx/014index_addressing.cc | 20 |
1 files changed, 15 insertions, 5 deletions
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) |