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coreboot-kgpe-d16/util/cbfstool/linux_trampoline.c

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Add a (b)zImage parser to cbfstool In the great tradition of LinuxBIOS this allows adding a kernel as payload. add-payload is extended to also allow adding an initial ramdisk (-I filename) and a command line (-C console=ttyS0). Change-Id: Iaca499a98b0adf0134e78d6bf020b6531a626aaa Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com> Signed-off-by: Patrick Georgi <patrick@georgi-clan.de> Reviewed-on: http://review.coreboot.org/3302 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2013-08-27 20:22:21 +02:00
/*
* linux_trampoline
*
* Copyright (C) 2013 Patrick Georgi <patrick@georgi-clan.de>
*
* 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
*/
#if 0
/* NOTE: THIS CODE MUST REMAIN POSITION INDEPENDENT
* IT SHOULDN'T USE THE STACK
* AND IN GENERAL EXPECT NOTHING BUT RAM TO WORK
*/
.code32
.data
cbfstool:linux_trampoline: config CS and DS segment descriptors The Linux trampoline code does not set up the segment descriptors for __BOOT_CS and __BOOT_DS as described in the Linux kernel documentation: ... a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; This is not a problem when launching a Linux payload from coreboot, as coreboot configures the segment descriptors at selectors 0x10 and 0x18. Coreboot configures these selectors in the ramstage to match what the Linux kernel expects (see coreboot/src/arch/x86/lib/c_start.S). When the cbfs payload is launched in other environments, SeaBIOS for example, the segment descriptors are configured differently and the cbfs Linux payload does not work. If the cbfs Linux payload is to be used in multiple environments should the trampoline needs to take care of the descriptors that Linux requires. This patch updates the Linux trampoline code to configure the 4G flat descriptors that Linux expects. The configuration is borrowed from the descriptor configs in coreboot/src/arch/x86/lib/c_start.S for selectors 0x10 and 0x18. The linux_trampoline code is slightly refractored by defining the trampoline entry address, 0x40000, as TRAMPOLINE_ENTRY_LOC. This definition is moved into a separate header file, linux_trampoline.h. This header file is now included by both the trampoline assembly language code and the trampoline loader C code. The trampoline assembly language code can now use TRAMPOLINE_ENTRY_LOC as scratch space for the sgdt CPU instruction. Testing Done: Verified the Linux payload is booted correctly in the following environments: 1. Coreboot -> Linux Payload 2. Coreboot -> SeaBIOS -> Linux Payload: (previously did not work) Change-Id: I888f74ff43073a6b7318f6713a8d4ecb804c0162 Signed-off-by: Curt Brune <curt@cumulusnetworks.com> Reviewed-on: http://review.coreboot.org/6796 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2014-08-29 19:43:36 +02:00
#include "linux_trampoline.h"
Add a (b)zImage parser to cbfstool In the great tradition of LinuxBIOS this allows adding a kernel as payload. add-payload is extended to also allow adding an initial ramdisk (-I filename) and a command line (-C console=ttyS0). Change-Id: Iaca499a98b0adf0134e78d6bf020b6531a626aaa Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com> Signed-off-by: Patrick Georgi <patrick@georgi-clan.de> Reviewed-on: http://review.coreboot.org/3302 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2013-08-27 20:22:21 +02:00
#define HEADER_SIG 0x4f49424c // LBIO little endian
#define CB_TAG_FORWARD 0x11
#define CB_TAG_MEMORY 0x1
#define CB_TAG_FRAMEBUFFER 0x12
#define E820_NR_OFFSET 0x1e8
#define LINUX_ENTRY_OFFSET 0x214
#define E820_OFFSET 0x2d0
.trampoline_start:
cld
xor %edx, %edx
mov $0, %ecx
.headerSearch:
mov $0x10000, %ebx
add %ecx, %ebx
mov (%ecx), %eax
cmp $HEADER_SIG, %eax
je .headerSearchDone // found the header
add $16, %ecx
cmp %ecx, %ebx
jne .headerSearch
.headerSearchDone:
cmp %ecx, %ebx // reached the end == not found anything?
je 2f // give up
// we assume the checksum is okay, no test
mov 4(%ecx), %ebx
add %ecx, %ebx // ebx = cb_header + header_bytes
mov 20(%ecx), %ecx // ecx = table_entries
.tableScan:
cmp $CB_TAG_FORWARD, (%ebx)
jne .testMemory
/* forward tag: assume 32bit pointer */
mov 8(%ebx), %ecx
jmp .headerSearch
.testMemory:
cmp $CB_TAG_MEMORY, (%ebx)
jne .testFramebuffer
/* memory tag: copy e820 map and entry count. also determine alt_mem_k */
mov 4(%ebx), %eax
sub $8, %eax
shr $2, %eax /* eax = number of dwords of e820 data */
cmp $(32 * 5), %eax /* linux wants at most 32 entries of 5 dwords */
jng 1f
mov $(32 * 5), %eax /* only copy 32 entries */
1:
mov %eax, %esi
mov $5, %edi
div %edi
mov %eax, (LINUX_PARAM_LOC + E820_NR_OFFSET)
mov %esi, %eax
xchg %eax, %ecx
lea 8(%ebx), %esi /* e820 data source */
mov $(LINUX_PARAM_LOC + E820_OFFSET), %edi
rep movsl
xchg %eax, %ecx
jmp .endScan
.testFramebuffer:
cmp $CB_TAG_FRAMEBUFFER, (%ebx)
jne .endScan
/* TODO: handle framebuffer tag */
.endScan:
add 4(%ebx), %ebx
dec %ecx
jnz .tableScan
cbfstool:linux_trampoline: config CS and DS segment descriptors The Linux trampoline code does not set up the segment descriptors for __BOOT_CS and __BOOT_DS as described in the Linux kernel documentation: ... a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; This is not a problem when launching a Linux payload from coreboot, as coreboot configures the segment descriptors at selectors 0x10 and 0x18. Coreboot configures these selectors in the ramstage to match what the Linux kernel expects (see coreboot/src/arch/x86/lib/c_start.S). When the cbfs payload is launched in other environments, SeaBIOS for example, the segment descriptors are configured differently and the cbfs Linux payload does not work. If the cbfs Linux payload is to be used in multiple environments should the trampoline needs to take care of the descriptors that Linux requires. This patch updates the Linux trampoline code to configure the 4G flat descriptors that Linux expects. The configuration is borrowed from the descriptor configs in coreboot/src/arch/x86/lib/c_start.S for selectors 0x10 and 0x18. The linux_trampoline code is slightly refractored by defining the trampoline entry address, 0x40000, as TRAMPOLINE_ENTRY_LOC. This definition is moved into a separate header file, linux_trampoline.h. This header file is now included by both the trampoline assembly language code and the trampoline loader C code. The trampoline assembly language code can now use TRAMPOLINE_ENTRY_LOC as scratch space for the sgdt CPU instruction. Testing Done: Verified the Linux payload is booted correctly in the following environments: 1. Coreboot -> Linux Payload 2. Coreboot -> SeaBIOS -> Linux Payload: (previously did not work) Change-Id: I888f74ff43073a6b7318f6713a8d4ecb804c0162 Signed-off-by: Curt Brune <curt@cumulusnetworks.com> Reviewed-on: http://review.coreboot.org/6796 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2014-08-29 19:43:36 +02:00
/* Setup basic code and data segment selectors for Linux
**
** Flat code segment descriptor:
** selector: 0x10
** base : 0x00000000
** limit : 0xFFFFFFFF
** type : code, execute, read
**
** Flat data segment descriptor:
** selector: 0x18
** base : 0x00000000
** limit : 0xFFFFFFFF
** type : data, read/write
**
** Use TRAMPOLINE_ENTRY_LOC as a scratchpad.
*/
mov $TRAMPOLINE_ENTRY_LOC, %eax
sgdt (%eax)
mov 2(%eax), %ebx
movl $0x0000ffff, 16(%ebx)
movl $0x00cf9b00, 20(%ebx)
movl $0x0000ffff, 24(%ebx)
movl $0x00cf9300, 28(%ebx)
Add a (b)zImage parser to cbfstool In the great tradition of LinuxBIOS this allows adding a kernel as payload. add-payload is extended to also allow adding an initial ramdisk (-I filename) and a command line (-C console=ttyS0). Change-Id: Iaca499a98b0adf0134e78d6bf020b6531a626aaa Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com> Signed-off-by: Patrick Georgi <patrick@georgi-clan.de> Reviewed-on: http://review.coreboot.org/3302 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2013-08-27 20:22:21 +02:00
/* finally: jump to kernel */
mov $LINUX_PARAM_LOC, %esi
jmp *(LINUX_PARAM_LOC + LINUX_ENTRY_OFFSET)
2:
hlt
jmp 2b
.trampoline_end:
.global trampoline_start, trampoline_size
trampoline_start:
.long .trampoline_start
trampoline_size:
.long .trampoline_end - .trampoline_start
#endif
/* The code above is hand-crafted to fit various contraints.
* To simplify porting, the below matches the above.
* When changing any code in here, compile the above as a .S
* file, objcopy it to binary and paste the result below (minus
* the last 8 bytes which are trampoline_start and trampoline_size).
*/
const unsigned char trampoline[] = {
0xfc, 0x31, 0xd2, 0xb9, 0x00, 0x00, 0x00, 0x00, 0xbb, 0x00, 0x00, 0x01, 0x00, 0x01, 0xcb, 0x8b,
0x01, 0x3d, 0x4c, 0x42, 0x49, 0x4f, 0x74, 0x07, 0x83, 0xc1, 0x10, 0x39, 0xcb, 0x75, 0xe9, 0x39,
cbfstool:linux_trampoline: config CS and DS segment descriptors The Linux trampoline code does not set up the segment descriptors for __BOOT_CS and __BOOT_DS as described in the Linux kernel documentation: ... a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; This is not a problem when launching a Linux payload from coreboot, as coreboot configures the segment descriptors at selectors 0x10 and 0x18. Coreboot configures these selectors in the ramstage to match what the Linux kernel expects (see coreboot/src/arch/x86/lib/c_start.S). When the cbfs payload is launched in other environments, SeaBIOS for example, the segment descriptors are configured differently and the cbfs Linux payload does not work. If the cbfs Linux payload is to be used in multiple environments should the trampoline needs to take care of the descriptors that Linux requires. This patch updates the Linux trampoline code to configure the 4G flat descriptors that Linux expects. The configuration is borrowed from the descriptor configs in coreboot/src/arch/x86/lib/c_start.S for selectors 0x10 and 0x18. The linux_trampoline code is slightly refractored by defining the trampoline entry address, 0x40000, as TRAMPOLINE_ENTRY_LOC. This definition is moved into a separate header file, linux_trampoline.h. This header file is now included by both the trampoline assembly language code and the trampoline loader C code. The trampoline assembly language code can now use TRAMPOLINE_ENTRY_LOC as scratch space for the sgdt CPU instruction. Testing Done: Verified the Linux payload is booted correctly in the following environments: 1. Coreboot -> Linux Payload 2. Coreboot -> SeaBIOS -> Linux Payload: (previously did not work) Change-Id: I888f74ff43073a6b7318f6713a8d4ecb804c0162 Signed-off-by: Curt Brune <curt@cumulusnetworks.com> Reviewed-on: http://review.coreboot.org/6796 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2014-08-29 19:43:36 +02:00
0xcb, 0x0f, 0x84, 0x85, 0x00, 0x00, 0x00, 0x8b, 0x59, 0x04, 0x01, 0xcb, 0x8b, 0x49, 0x14, 0x83,
0x3b, 0x11, 0x75, 0x05, 0x8b, 0x4b, 0x08, 0xeb, 0xcf, 0x83, 0x3b, 0x01, 0x75, 0x33, 0x8b, 0x43,
0x04, 0x83, 0xe8, 0x08, 0xc1, 0xe8, 0x02, 0x3d, 0xa0, 0x00, 0x00, 0x00, 0x7e, 0x05, 0xb8, 0xa0,
0x00, 0x00, 0x00, 0x89, 0xc6, 0xbf, 0x05, 0x00, 0x00, 0x00, 0xf7, 0xf7, 0xa3, 0xe8, 0x01, 0x09,
0x00, 0x89, 0xf0, 0x91, 0x8d, 0x73, 0x08, 0xbf, 0xd0, 0x02, 0x09, 0x00, 0xf3, 0xa5, 0x91, 0xeb,
0x05, 0x83, 0x3b, 0x12, 0x75, 0x00, 0x03, 0x5b, 0x04, 0x49, 0x75, 0xb3, 0xb8, 0x00, 0x00, 0x04,
0x00, 0x0f, 0x01, 0x00, 0x8b, 0x58, 0x02, 0xc7, 0x43, 0x10, 0xff, 0xff, 0x00, 0x00, 0xc7, 0x43,
0x14, 0x00, 0x9b, 0xcf, 0x00, 0xc7, 0x43, 0x18, 0xff, 0xff, 0x00, 0x00, 0xc7, 0x43, 0x1c, 0x00,
0x93, 0xcf, 0x00, 0xbe, 0x00, 0x00, 0x09, 0x00, 0xff, 0x25, 0x14, 0x02, 0x09, 0x00, 0xf4, 0xeb,
0xfd
Add a (b)zImage parser to cbfstool In the great tradition of LinuxBIOS this allows adding a kernel as payload. add-payload is extended to also allow adding an initial ramdisk (-I filename) and a command line (-C console=ttyS0). Change-Id: Iaca499a98b0adf0134e78d6bf020b6531a626aaa Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com> Signed-off-by: Patrick Georgi <patrick@georgi-clan.de> Reviewed-on: http://review.coreboot.org/3302 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2013-08-27 20:22:21 +02:00
};
cbfstool: Fix build errors when building with clang Now that we can set CC to an arbitrary compiler, fix issues that clang finds. Luckily, there were only two trivial errors. Change-Id: I0fd1f0f263a8ab7004f39cd36ed42d1a1cba5c04 Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-on: http://review.coreboot.org/5081 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2014-01-29 21:27:52 +01:00
const void * const trampoline_start = &trampoline;
Add a (b)zImage parser to cbfstool In the great tradition of LinuxBIOS this allows adding a kernel as payload. add-payload is extended to also allow adding an initial ramdisk (-I filename) and a command line (-C console=ttyS0). Change-Id: Iaca499a98b0adf0134e78d6bf020b6531a626aaa Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com> Signed-off-by: Patrick Georgi <patrick@georgi-clan.de> Reviewed-on: http://review.coreboot.org/3302 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2013-08-27 20:22:21 +02:00
const unsigned long trampoline_size = sizeof trampoline;