Add a few missing license headers based on svn logs, and also add a

few more code comments to src/cpu/x86/*.inc files.
 
Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5859 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Uwe Hermann 2010-09-27 17:53:17 +00:00
parent da28cd8542
commit 5211a7023e
4 changed files with 111 additions and 18 deletions

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@ -1,10 +1,39 @@
/* preserve BIST in %eax */ /*
* This file is part of the coreboot project.
*
* Copyright (C) 2002 Eric Biederman <ebiederm@xmission.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
__fpu_start: __fpu_start:
/* Preserve BIST. */
movl %eax, %ebp movl %eax, %ebp
/* Disable floating point emulation */ /*
* Clear the CR0[2] bit (the "Emulation" flag, EM).
*
* This indicates that the processor has an (internal or external)
* x87 FPU, i.e. floating point operations will be executed by the
* hardware (and not emulated in software).
*
* Additionally, if this bit is not cleared, MMX/SSE instructions won't
* work, i.e., they will trigger an invalid opcode exception (#UD).
*/
movl %cr0, %eax movl %cr0, %eax
andl $~(1 << 2), %eax andl $~(1 << 2), %eax
movl %eax, %cr0 movl %eax, %cr0
/* Restore BIST. */
movl %ebp, %eax movl %ebp, %eax

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@ -1,2 +1,24 @@
/* Clear out an mmx state */ /*
* This file is part of the coreboot project.
*
* Copyright (C) 2002 Eric Biederman <ebiederm@xmission.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* Execute the EMMS (Empty MMX Technology State) instruction.
*/
emms emms

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@ -1,8 +1,26 @@
/* /*
* Put the processor back into a reset state * This file is part of the coreboot project.
* with respect to the xmm registers. *
* Copyright (C) 2002 Eric Biederman <ebiederm@xmission.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/ */
/*
* Put the processor back into a reset state
* with respect to the XMM registers.
*/
xorps %xmm0, %xmm0 xorps %xmm0, %xmm0
xorps %xmm1, %xmm1 xorps %xmm1, %xmm1
xorps %xmm2, %xmm2 xorps %xmm2, %xmm2
@ -12,7 +30,15 @@
xorps %xmm6, %xmm6 xorps %xmm6, %xmm6
xorps %xmm7, %xmm7 xorps %xmm7, %xmm7
/* Disable sse instructions */ /*
* Disable SSE instructions.
*
* Clear CR4[9] (OSFXSR) and CR4[10] (OSXMMEXCPT) so that the
* processor can no longer execute SSE instructions, and unmasked
* SIMD floating point exceptions will generate an invalid opcode
* exception (#UD).
*/
movl %cr4, %eax movl %cr4, %eax
andl $~(3 << 9), %eax andl $~(3 << 9), %eax
movl %eax, %cr4 movl %eax, %cr4

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@ -1,14 +1,30 @@
/* preserve BIST in %eax */
movl %eax, %ebp
/* /*
* Enable the use of the xmm registers * This file is part of the coreboot project.
*
* Copyright (C) 2002 Eric Biederman <ebiederm@xmission.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/ */
/* Enable sse instructions */ /* Preserve BIST. */
movl %eax, %ebp
/* Enable SSE instructions. */
movl %cr4, %eax movl %cr4, %eax
orl $(1 << 9), %eax orl $(1 << 9), %eax
movl %eax, %cr4 movl %eax, %cr4
/* Restore BIST. */
movl %ebp, %eax movl %ebp, %eax