Machine code: Difference between revisions
Content added Content deleted
m (Clarified the program a little bit.) |
(→{{header|Go}}: Now uses actual x64 opcodes rather than x86/x64 'glue code' .) |
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This task requires the use of 'cgo' which enables Go to interface with C code by importing a pseudo-package called "C". |
This task requires the use of 'cgo' which enables Go to interface with C code by importing a pseudo-package called "C". |
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Although Go supports both 32-bit and 64-bit architectures, I'm writing this on a 64-bit Ubuntu |
Although Go supports both 32-bit and 64-bit architectures, I'm writing this on a 64-bit Ubuntu 20.04 system. I'm therefore using x64 opcodes rather than the x86 (32-bit) opcodes listed in the task description. |
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There doesn't appear to be a way to cast a pointer to a native buffer to a Go function pointer so that the machine code can be run directly. I've therefore written a C function to perform this step and embedded it in the program which 'cgo' allows us to do. |
There doesn't appear to be a way to cast a pointer to a native buffer to a Go function pointer so that the machine code can be run directly. I've therefore written a C function to perform this step and embedded it in the program which 'cgo' allows us to do. |
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func main() { |
func main() { |
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code := []byte{ |
code := []byte{ |
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0x55, 0x48, 0x89, 0xe5, 0x89, 0x7d, |
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0xfc, 0x89, 0x75, 0xf8, 0x8b, 0x75, |
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0xfc, 0x03, 0x75, 0xf8, 0x89, 0x75, |
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0xf4, 0x8b, 0x45, 0xf4, 0x5d, 0xc3, |
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72, 193, 224, 32, |
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80, |
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139, 68, 36, 4, 3, 68, 36, 8, // Rosetta task code |
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76, 137, 227, // Get result |
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137, 195, |
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72, 193, 227, 4, |
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128, 203, 2, |
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72, 131, 196, 16, // Clean up stack |
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195, // Return |
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} |
} |
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le := len(code) |
le := len(code) |
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