diff options
Diffstat (limited to 'tboot/bits.S')
| -rw-r--r-- | tboot/bits.S | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/tboot/bits.S b/tboot/bits.S new file mode 100644 index 0000000..0cf6ea1 --- /dev/null +++ b/tboot/bits.S @@ -0,0 +1,166 @@ +/* + * bits.S: Assembly support routines and bits. + * + * Copyright (c) 2017 Assured Information Security. + * + * Ross Philipson <philipsonr@ainfosec.com> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * * Neither the name of the Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <config.h> + +#define REF(x) x(%rip) + +#define SOFF 16 + +ENTRY(print_test_chars) + pushq %rcx + pushq %rdx + xorq %rcx, %rcx +1: + cmpb $5, %cl + jz 2f + movw $0x3f8, %dx + addw $5, %dx +3: + inb %dx, %al + testb $0x20, %al + jz 3b + movw $0x3f8, %dx + movb $0x41, %al + addb %cl, %al + outb %al, %dx + incb %cl + jmp 1b +2: + popq %rdx + popq %rcx + ret + +ENTRY(memcpy) + pushq %rbp + movq %rsp, %rbp + movq %rcx, SOFF(%rbp) # dst + movq %rdx, SOFF+8(%rbp) # src + movq %r8, SOFF+16(%rbp) # size + + movq %rcx, %rdi + movq %rdx, %rsi + movq %r8, %rcx + shrq $3, %rcx + cld + rep + movsq # mov quad words forward + movq %r8, %rcx + andq $7, %rcx + rep + movsb # mov remaining bytes forward + popq %rbp + ret + +ENTRY(read_msr) + pushq %rdx + /* ECX already has MSR number, go for it */ + rdmsr + movq $0xffffffff, %rcx + andq %rcx, %rax + shlq $32, %rdx + movq $0xffffffff00000000, %rcx + andq %rcx, %rdx + orq %rdx, %rax + popq %rdx + ret + +ENTRY(write_msr) + pushq %rax + movq %rdx, %rax + shrq $32, %rdx + /* ECX already has MSR number */ + wrmsr + popq %rax + ret + +ENTRY(read_tsc) + rdtsc + movq $0xffffffff, %rcx + andq %rcx, %rax + shlq $32, %rdx + movq $0xffffffff00000000, %rcx + andq %rcx, %rdx + orq %rdx, %rax + ret + +/* + * Mutex code ported to 64b from: + * $OpenBSD: mutex.S,v 1.6 2009/04/27 21:48:56 kettenis Exp $ + * + * Copyright (c) 2004 Artur Grabowski <art@openbsd.org> + * All rights reserved. + * + * BSD 2-Clause + */ + +ENTRY(mtx_init) + pushq %rbp + movq %rsp, %rbp + movq %rcx, SOFF(%rbp) # home var + movq $0, (%rcx) + popq %rbp + ret + +ENTRY(mtx_enter) + pushq %rbp + movq %rsp, %rbp +1: movq %rcx, SOFF(%rbp) # home var + /* + * %rcx contains the mtx as passed from caller + */ + movq $1, %rax + xchgq %rax, (%rcx) # test_and_set(mtx->mtx_lock) + testq %rax, %rax # if (already held) + jnz 2f + popq %rbp + ret +2: pause + movq (%rcx), %rax + testq %rax, %rax + jz 1b + jmp 2b + +ENTRY(mtx_leave) + pushq %rbp + movq %rsp, %rbp + movq %rcx, SOFF(%rbp) # home var + movq $0, (%rcx) + popq %rbp + ret + +ENTRY(get_rip) + movq (%rsp), %rax + ret |