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package cmd
import (
"debug/elf"
"fmt"
"github.com/urfave/cli/v2"
"github.com/ethereum-optimism/optimism/cannon/mipsevm"
)
var (
LoadELFPathFlag = &cli.PathFlag{
Name: "path",
Usage: "Path to 32-bit big-endian MIPS ELF file",
TakesFile: true,
Required: true,
}
LoadELFPatchFlag = &cli.StringSliceFlag{
Name: "patch",
Usage: "Type of patching to do",
Value: cli.NewStringSlice("go", "stack"),
Required: false,
}
LoadELFOutFlag = &cli.PathFlag{
Name: "out",
Usage: "Output path to write JSON state to. State is dumped to stdout if set to -. Not written if empty.",
Value: "state.json",
Required: false,
}
LoadELFMetaFlag = &cli.PathFlag{
Name: "meta",
Usage: "Write metadata file, for symbol lookup during program execution. None if empty.",
Value: "meta.json",
Required: false,
}
)
func LoadELF(ctx *cli.Context) error {
elfPath := ctx.Path(LoadELFPathFlag.Name)
elfProgram, err := elf.Open(elfPath)
if err != nil {
return fmt.Errorf("failed to open ELF file %q: %w", elfPath, err)
}
if elfProgram.Machine != elf.EM_MIPS {
return fmt.Errorf("ELF is not big-endian MIPS R3000, but got %q", elfProgram.Machine.String())
}
state, err := mipsevm.LoadELF(elfProgram)
if err != nil {
return fmt.Errorf("failed to load ELF data into VM state: %w", err)
}
for _, typ := range ctx.StringSlice(LoadELFPatchFlag.Name) {
switch typ {
case "stack":
err = mipsevm.PatchStack(state)
case "go":
err = mipsevm.PatchGo(elfProgram, state)
default:
return fmt.Errorf("unrecognized form of patching: %q", typ)
}
if err != nil {
return fmt.Errorf("failed to apply patch %s: %w", typ, err)
}
}
meta, err := mipsevm.MakeMetadata(elfProgram)
if err != nil {
return fmt.Errorf("failed to compute program metadata: %w", err)
}
if err := writeJSON[*mipsevm.Metadata](ctx.Path(LoadELFMetaFlag.Name), meta); err != nil {
return fmt.Errorf("failed to output metadata: %w", err)
}
return writeJSON[*mipsevm.State](ctx.Path(LoadELFOutFlag.Name), state)
}
var LoadELFCommand = &cli.Command{
Name: "load-elf",
Usage: "Load ELF file into Cannon JSON state",
Description: "Load ELF file into Cannon JSON state, optionally patch out functions",
Action: LoadELF,
Flags: []cli.Flag{
LoadELFPathFlag,
LoadELFPatchFlag,
LoadELFOutFlag,
LoadELFMetaFlag,
},
}