a73b93157f
It encourages users from writing to the FSF without giving an address. Linux also prefers to drop that and their checkpatch.pl (that we imported) looks out for that. This is the result of util/scripts/no-fsf-addresses.sh with no further editing. Change-Id: Ie96faea295fe001911d77dbc51e9a6789558fbd6 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Reviewed-on: http://review.coreboot.org/11888 Tested-by: build bot (Jenkins) Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
165 lines
4.6 KiB
C
165 lines
4.6 KiB
C
/*
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* linux_trampoline
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*
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* Copyright (C) 2013 Patrick Georgi <patrick@georgi-clan.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#if 0
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/* NOTE: THIS CODE MUST REMAIN POSITION INDEPENDENT
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* IT SHOULDN'T USE THE STACK
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* AND IN GENERAL EXPECT NOTHING BUT RAM TO WORK
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*/
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.code32
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.data
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#include "linux_trampoline.h"
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#define HEADER_SIG 0x4f49424c // LBIO little endian
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#define CB_TAG_FORWARD 0x11
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#define CB_TAG_MEMORY 0x1
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#define CB_TAG_FRAMEBUFFER 0x12
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#define E820_NR_OFFSET 0x1e8
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#define LINUX_ENTRY_OFFSET 0x214
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#define E820_OFFSET 0x2d0
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.trampoline_start:
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cld
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xor %edx, %edx
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mov $0, %ecx
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.headerSearch:
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mov $0x10000, %ebx
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add %ecx, %ebx
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mov (%ecx), %eax
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cmp $HEADER_SIG, %eax
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je .headerSearchDone // found the header
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add $16, %ecx
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cmp %ecx, %ebx
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jne .headerSearch
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.headerSearchDone:
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cmp %ecx, %ebx // reached the end == not found anything?
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je 2f // give up
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// we assume the checksum is okay, no test
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mov 4(%ecx), %ebx
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add %ecx, %ebx // ebx = cb_header + header_bytes
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mov 20(%ecx), %ecx // ecx = table_entries
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.tableScan:
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cmp $CB_TAG_FORWARD, (%ebx)
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jne .testMemory
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/* forward tag: assume 32bit pointer */
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mov 8(%ebx), %ecx
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jmp .headerSearch
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.testMemory:
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cmp $CB_TAG_MEMORY, (%ebx)
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jne .testFramebuffer
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/* memory tag: copy e820 map and entry count. also determine alt_mem_k */
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mov 4(%ebx), %eax
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sub $8, %eax
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shr $2, %eax /* eax = number of dwords of e820 data */
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cmp $(32 * 5), %eax /* linux wants at most 32 entries of 5 dwords */
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jng 1f
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mov $(32 * 5), %eax /* only copy 32 entries */
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1:
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mov %eax, %esi
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mov $5, %edi
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div %edi
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mov %eax, (LINUX_PARAM_LOC + E820_NR_OFFSET)
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mov %esi, %eax
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xchg %eax, %ecx
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lea 8(%ebx), %esi /* e820 data source */
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mov $(LINUX_PARAM_LOC + E820_OFFSET), %edi
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rep movsl
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xchg %eax, %ecx
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jmp .endScan
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.testFramebuffer:
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cmp $CB_TAG_FRAMEBUFFER, (%ebx)
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jne .endScan
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/* TODO: handle framebuffer tag */
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.endScan:
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add 4(%ebx), %ebx
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dec %ecx
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jnz .tableScan
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/* Setup basic code and data segment selectors for Linux
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**
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** Flat code segment descriptor:
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** selector: 0x10
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** base : 0x00000000
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** limit : 0xFFFFFFFF
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** type : code, execute, read
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**
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** Flat data segment descriptor:
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** selector: 0x18
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** base : 0x00000000
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** limit : 0xFFFFFFFF
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** type : data, read/write
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**
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** Use TRAMPOLINE_ENTRY_LOC as a scratchpad.
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*/
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mov $TRAMPOLINE_ENTRY_LOC, %eax
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sgdt (%eax)
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mov 2(%eax), %ebx
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movl $0x0000ffff, 16(%ebx)
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movl $0x00cf9b00, 20(%ebx)
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movl $0x0000ffff, 24(%ebx)
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movl $0x00cf9300, 28(%ebx)
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/* finally: jump to kernel */
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mov $LINUX_PARAM_LOC, %esi
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jmp *(LINUX_PARAM_LOC + LINUX_ENTRY_OFFSET)
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2:
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hlt
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jmp 2b
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.trampoline_end:
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.global trampoline_start, trampoline_size
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trampoline_start:
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.long .trampoline_start
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trampoline_size:
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.long .trampoline_end - .trampoline_start
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#endif
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/* The code above is hand-crafted to fit various contraints.
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* To simplify porting, the below matches the above.
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* When changing any code in here, compile the above as a .S
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* file, objcopy it to binary and paste the result below (minus
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* the last 8 bytes which are trampoline_start and trampoline_size).
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*/
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const unsigned char trampoline[] = {
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0xfc, 0x31, 0xd2, 0xb9, 0x00, 0x00, 0x00, 0x00, 0xbb, 0x00, 0x00, 0x01, 0x00, 0x01, 0xcb, 0x8b,
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0x01, 0x3d, 0x4c, 0x42, 0x49, 0x4f, 0x74, 0x07, 0x83, 0xc1, 0x10, 0x39, 0xcb, 0x75, 0xe9, 0x39,
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0xcb, 0x0f, 0x84, 0x85, 0x00, 0x00, 0x00, 0x8b, 0x59, 0x04, 0x01, 0xcb, 0x8b, 0x49, 0x14, 0x83,
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0x3b, 0x11, 0x75, 0x05, 0x8b, 0x4b, 0x08, 0xeb, 0xcf, 0x83, 0x3b, 0x01, 0x75, 0x33, 0x8b, 0x43,
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0x04, 0x83, 0xe8, 0x08, 0xc1, 0xe8, 0x02, 0x3d, 0xa0, 0x00, 0x00, 0x00, 0x7e, 0x05, 0xb8, 0xa0,
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0x00, 0x00, 0x00, 0x89, 0xc6, 0xbf, 0x05, 0x00, 0x00, 0x00, 0xf7, 0xf7, 0xa3, 0xe8, 0x01, 0x09,
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0x00, 0x89, 0xf0, 0x91, 0x8d, 0x73, 0x08, 0xbf, 0xd0, 0x02, 0x09, 0x00, 0xf3, 0xa5, 0x91, 0xeb,
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0x05, 0x83, 0x3b, 0x12, 0x75, 0x00, 0x03, 0x5b, 0x04, 0x49, 0x75, 0xb3, 0xb8, 0x00, 0x00, 0x04,
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0x00, 0x0f, 0x01, 0x00, 0x8b, 0x58, 0x02, 0xc7, 0x43, 0x10, 0xff, 0xff, 0x00, 0x00, 0xc7, 0x43,
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0x14, 0x00, 0x9b, 0xcf, 0x00, 0xc7, 0x43, 0x18, 0xff, 0xff, 0x00, 0x00, 0xc7, 0x43, 0x1c, 0x00,
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0x93, 0xcf, 0x00, 0xbe, 0x00, 0x00, 0x09, 0x00, 0xff, 0x25, 0x14, 0x02, 0x09, 0x00, 0xf4, 0xeb,
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0xfd
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};
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const void * const trampoline_start = &trampoline;
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const unsigned long trampoline_size = sizeof trampoline;
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