1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
# parse the embedded ELF (physical address from elf_phys()) and run it in ring 3
const PT_LOAD = 1
const PAGE_FLAGS = 6 # WRITE | USER
fn cmd_run() do
const base = elf_phys()
if mem_read(base, 4) != 0x464c457f do
puts("run: not an ELF\n")
return :nil
end
const entry = mem_read(base + 24, 8)
const phoff = mem_read(base + 32, 8)
const phnum = mem_read(base + 56, 2)
const phentsize = mem_read(base + 54, 2)
const as = as_create()
for i in 0..phnum do
const ph = base + phoff + i * phentsize
if mem_read(ph, 4) == PT_LOAD do
const offset = mem_read(ph + 8, 8)
const vaddr = mem_read(ph + 16, 8)
const filesz = mem_read(ph + 32, 8)
const memsz = mem_read(ph + 40, 8)
let off = 0
while off < memsz do
const frame = frame_alloc()
mem_zero(frame, 4096)
if off < filesz do
const left = filesz - off
mem_copy(frame, base + offset + off, if left > 4096 4096 else left)
end
as_map(as, vaddr + off, frame, PAGE_FLAGS)
off = off + 4096
end
end
end
const stack_top = 0x7fff0000
as_map(as, stack_top - 4096, frame_alloc(), PAGE_FLAGS)
proc_run(as, entry, stack_top)
end
|
