diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ia64/kernel/efi_stub.S |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/ia64/kernel/efi_stub.S')
-rw-r--r-- | arch/ia64/kernel/efi_stub.S | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/ia64/kernel/efi_stub.S b/arch/ia64/kernel/efi_stub.S new file mode 100644 index 000000000000..5a7fe70212a9 --- /dev/null +++ b/arch/ia64/kernel/efi_stub.S | |||
@@ -0,0 +1,86 @@ | |||
1 | /* | ||
2 | * EFI call stub. | ||
3 | * | ||
4 | * Copyright (C) 1999-2001 Hewlett-Packard Co | ||
5 | * David Mosberger <davidm@hpl.hp.com> | ||
6 | * | ||
7 | * This stub allows us to make EFI calls in physical mode with interrupts | ||
8 | * turned off. We need this because we can't call SetVirtualMap() until | ||
9 | * the kernel has booted far enough to allow allocation of struct vma_struct | ||
10 | * entries (which we would need to map stuff with memory attributes other | ||
11 | * than uncached or writeback...). Since the GetTime() service gets called | ||
12 | * earlier than that, we need to be able to make physical mode EFI calls from | ||
13 | * the kernel. | ||
14 | */ | ||
15 | |||
16 | /* | ||
17 | * PSR settings as per SAL spec (Chapter 8 in the "IA-64 System | ||
18 | * Abstraction Layer Specification", revision 2.6e). Note that | ||
19 | * psr.dfl and psr.dfh MUST be cleared, despite what this manual says. | ||
20 | * Otherwise, SAL dies whenever it's trying to do an IA-32 BIOS call | ||
21 | * (the br.ia instruction fails unless psr.dfl and psr.dfh are | ||
22 | * cleared). Fortunately, SAL promises not to touch the floating | ||
23 | * point regs, so at least we don't have to save f2-f127. | ||
24 | */ | ||
25 | #define PSR_BITS_TO_CLEAR \ | ||
26 | (IA64_PSR_I | IA64_PSR_IT | IA64_PSR_DT | IA64_PSR_RT | \ | ||
27 | IA64_PSR_DD | IA64_PSR_SS | IA64_PSR_RI | IA64_PSR_ED | \ | ||
28 | IA64_PSR_DFL | IA64_PSR_DFH) | ||
29 | |||
30 | #define PSR_BITS_TO_SET \ | ||
31 | (IA64_PSR_BN) | ||
32 | |||
33 | #include <asm/processor.h> | ||
34 | #include <asm/asmmacro.h> | ||
35 | |||
36 | /* | ||
37 | * Inputs: | ||
38 | * in0 = address of function descriptor of EFI routine to call | ||
39 | * in1..in7 = arguments to routine | ||
40 | * | ||
41 | * Outputs: | ||
42 | * r8 = EFI_STATUS returned by called function | ||
43 | */ | ||
44 | |||
45 | GLOBAL_ENTRY(efi_call_phys) | ||
46 | .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8) | ||
47 | alloc loc1=ar.pfs,8,7,7,0 | ||
48 | ld8 r2=[in0],8 // load EFI function's entry point | ||
49 | mov loc0=rp | ||
50 | .body | ||
51 | ;; | ||
52 | mov loc2=gp // save global pointer | ||
53 | mov loc4=ar.rsc // save RSE configuration | ||
54 | mov ar.rsc=0 // put RSE in enforced lazy, LE mode | ||
55 | ;; | ||
56 | ld8 gp=[in0] // load EFI function's global pointer | ||
57 | movl r16=PSR_BITS_TO_CLEAR | ||
58 | mov loc3=psr // save processor status word | ||
59 | movl r17=PSR_BITS_TO_SET | ||
60 | ;; | ||
61 | or loc3=loc3,r17 | ||
62 | mov b6=r2 | ||
63 | ;; | ||
64 | andcm r16=loc3,r16 // get psr with IT, DT, and RT bits cleared | ||
65 | br.call.sptk.many rp=ia64_switch_mode_phys | ||
66 | .ret0: mov out4=in5 | ||
67 | mov out0=in1 | ||
68 | mov out1=in2 | ||
69 | mov out2=in3 | ||
70 | mov out3=in4 | ||
71 | mov out5=in6 | ||
72 | mov out6=in7 | ||
73 | mov loc5=r19 | ||
74 | mov loc6=r20 | ||
75 | br.call.sptk.many rp=b6 // call the EFI function | ||
76 | .ret1: mov ar.rsc=0 // put RSE in enforced lazy, LE mode | ||
77 | mov r16=loc3 | ||
78 | mov r19=loc5 | ||
79 | mov r20=loc6 | ||
80 | br.call.sptk.many rp=ia64_switch_mode_virt // return to virtual mode | ||
81 | .ret2: mov ar.rsc=loc4 // restore RSE configuration | ||
82 | mov ar.pfs=loc1 | ||
83 | mov rp=loc0 | ||
84 | mov gp=loc2 | ||
85 | br.ret.sptk.many rp | ||
86 | END(efi_call_phys) | ||