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package main
import (
"os"
"strings"
)
func main() {
for _, arg := range os.Args[1:] {
tempData, err := os.CreateTemp("", "data*")
Check(err)
dName := tempData.Name()
defer os.Remove(dName)
tempRoData, err := os.CreateTemp("", "rodata*")
Check(err)
rName := tempRoData.Name()
defer os.Remove(rName)
tempText, err := os.CreateTemp("", "text*")
Check(err)
tName := tempText.Name()
defer os.Remove(tName)
// First pass to find the address of all labels and encode the data
LabelFind(arg, tempData, tempRoData)
var names [3]string
var PHeaders [4]ProgramHeader
i := 0
n := 0
if SectionPos[TEXT] > 0 {
PHeaders[i] = ProgramHeader{PT_LOAD, 0, 0, 0,
uint32(SectionPos[TEXT]), uint32(SectionPos[TEXT]), PF_READ +
PF_EXEC, 0}
names[i] = tName
i++
n++
// Second pass to assemble the instructions.
Assemble(arg, tempText)
}
if SectionPos[DATA] > 0 {
PHeaders[i] = ProgramHeader{PT_LOAD, 0, 0, 0,
uint32(SectionPos[DATA]), uint32(SectionPos[DATA]), PF_READ +
PF_WRITE, 0}
names[i] = dName
i++
n++
}
if SectionPos[RODATA] > 0 {
PHeaders[i] = ProgramHeader{PT_LOAD, 0, 0, 0,
uint32(SectionPos[RODATA]), uint32(SectionPos[RODATA]), PF_READ, 0}
names[i] = rName
i++
n++
}
if SectionPos[BSS] > 0 {
PHeaders[i] = ProgramHeader{PT_LOAD, 0, 0, 0, 0,
uint32(SectionPos[BSS]), PF_READ + PF_WRITE, 0}
i++
}
var fOffset, mOffset uint32 = 0, 0
for j, p := range PHeaders[:i] {
PHeaders[j].offset = uint32(i*PHENSIZE) + fOffset
fOffset += p.filesz
PHeaders[j].vaddr = mOffset
mOffset += p.memsz
}
EHeader := EHInit(0, uint16(i))
WriteBinary(arg, EHeader, PHeaders[:i], names[:n])
}
}
func WriteBinary(path string, e ElfHeader, ps []ProgramHeader, ns []string) {
out, err := os.Create(strings.ReplaceAll(path, ".asm", ".bin"))
Check(err)
defer out.Close()
_, err = out.Write(e.ToBytes())
Check(err)
for _, p := range ps {
_, err = out.Write(p.ToBytes())
Check(err)
}
for _, name := range ns {
b, err := os.ReadFile(name)
Check(err)
_, err = out.Write(b)
Check(err)
}
}
func Check(err error) {
if err != nil {
panic(err)
}
}
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