1	# bend-osdev-acpi, gas.bend: the Generic Address Structure (ACPI 6.5,
2	# section 5.2.3.2), 12 bytes:
3	#
4	#   offset  size  field
5	#        0     1  Address Space ID (0 system memory, 1 system I/O, 2 PCI
6	#                 configuration space, 3 embedded controller, 4 SMBus,
7	#                 5 CMOS, 6 PCI BAR target, 7 IPMI, 8 GPIO, 9 generic
8	#                 serial bus, 10 PCC, 11 PRM, 0x7F functional fixed hardware)
9	#        1     1  Register Bit Width
10	#        2     1  Register Bit Offset
11	#        3     1  Access Size (0 undefined, 1 byte, 2 word, 3 dword, 4 qword)
12	#        4     8  Address
13	import Base
14	import bend-osdev-word64@0.1.1.1/word64.bend as W
15	import bend-osdev-bytes@0.1.1.1/bytes.bend as B
16	import ./fields.bend as F
17	
18	type AcpiGas is Data:
19	  AcpiGas{space: U32, bit_width: U32, bit_offset: U32, access_size: U32, address: W.W64}
20	
21	def AcpiGas.space_memory() -> U32:
22	  0
23	
24	def AcpiGas.space_io() -> U32:
25	  1
26	
27	def AcpiGas.space_pci_config() -> U32:
28	  2
29	
30	def AcpiGas.space_ec() -> U32:
31	  3
32	
33	def AcpiGas.space_ffixedhw() -> U32:
34	  127
35	
36	def AcpiGas.size() -> Nat:
37	  12n
38	
39	# the structure at offset i of o
40	def AcpiGas.at(+o: B.Octets, +i: Nat) -> AcpiGas:
41	  AcpiGas{F.AcpiF.u8(o, i), F.AcpiF.u8(o, Nat.add(i, 1n)), F.AcpiF.u8(o, Nat.add(i, 2n)), F.AcpiF.u8(o, Nat.add(i, 3n)), F.AcpiF.u64(o, Nat.add(i, 4n))}
42	
43	def AcpiGas.encode(g: AcpiGas) -> B.Octets:
44	  match g:
45	    case AcpiGas{s, w, off, a, addr}:
46	      B.Octets.append(B.Octets.of_list([s, w, off, a]), B.Octets.le64(addr))
47	
48	def AcpiGas.zero() -> AcpiGas:
49	  AcpiGas{0, 0, 0, 0, W.W64.zero()}
50	
51	def AcpiGas.address(g: AcpiGas) -> W.W64:
52	  match g:
53	    case AcpiGas{s, w, off, a, addr}:
54	      addr
55	
56	def AcpiGas.space(g: AcpiGas) -> U32:
57	  match g:
58	    case AcpiGas{s, w, off, a, addr}:
59	      s
60	
61	# no register: the address is zero
62	def AcpiGas.is_null(g: AcpiGas) -> Bool:
63	  W.W64.is_zero(AcpiGas.address(g))
64	
65	# a system I/O register block at a 32-bit port address, n bytes long (how
66	# the FADT's ACPI 1.0 block fields are read as Generic Addresses)
67	def AcpiGas.io_block(port: U32, n: U32) -> AcpiGas:
68	  AcpiGas{1, U32.and(255, U32.mul(n, 8)), 0, 0, W.W64.from_u32(port)}
69	
70	def AcpiGas.show(g: AcpiGas) -> String:
71	  match g:
72	    case AcpiGas{s, w, off, a, addr}:
73	      "{" ++ U32.show(s) ++ " " ++ U32.show(w) ++ " " ++ U32.show(off) ++ " " ++ U32.show(a) ++ " " ++ W.W64.show_hex(addr) ++ "}"