optionrom: add new PVH option rom

The new pvh.bin option rom can be used with SeaBIOS to boot
uncompressed kernel using the x86/HVM direct boot ABI.

pvh.S contains the entry point of the option rom. It runs
in real mode, loads the e820 table querying the BIOS, and
then it switches to 32bit protected mode and jumps to the
pvh_load_kernel() written in pvh_main.c.
pvh_load_kernel() loads the cmdline and kernel entry_point
using fw_cfg, then it looks for RSDP, fills the
hvm_start_info required by x86/HVM ABI, and finally jumps
to the kernel entry_point.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
This commit is contained in:
Stefano Garzarella 2019-01-18 13:01:41 +01:00 committed by Paolo Bonzini
parent 6dfa01437b
commit 2785dc7b17
6 changed files with 325 additions and 2 deletions

4
.gitignore vendored
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@ -103,6 +103,10 @@
/pc-bios/optionrom/linuxboot_dma.bin /pc-bios/optionrom/linuxboot_dma.bin
/pc-bios/optionrom/linuxboot_dma.raw /pc-bios/optionrom/linuxboot_dma.raw
/pc-bios/optionrom/linuxboot_dma.img /pc-bios/optionrom/linuxboot_dma.img
/pc-bios/optionrom/pvh.asm
/pc-bios/optionrom/pvh.bin
/pc-bios/optionrom/pvh.raw
/pc-bios/optionrom/pvh.img
/pc-bios/optionrom/multiboot.asm /pc-bios/optionrom/multiboot.asm
/pc-bios/optionrom/multiboot.bin /pc-bios/optionrom/multiboot.bin
/pc-bios/optionrom/multiboot.raw /pc-bios/optionrom/multiboot.raw

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@ -673,7 +673,7 @@ efi-e1000.rom efi-eepro100.rom efi-ne2k_pci.rom \
efi-pcnet.rom efi-rtl8139.rom efi-virtio.rom \ efi-pcnet.rom efi-rtl8139.rom efi-virtio.rom \
efi-e1000e.rom efi-vmxnet3.rom \ efi-e1000e.rom efi-vmxnet3.rom \
bamboo.dtb canyonlands.dtb petalogix-s3adsp1800.dtb petalogix-ml605.dtb \ bamboo.dtb canyonlands.dtb petalogix-s3adsp1800.dtb petalogix-ml605.dtb \
multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin \ multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin pvh.bin \
s390-ccw.img s390-netboot.img \ s390-ccw.img s390-netboot.img \
spapr-rtas.bin slof.bin skiboot.lid \ spapr-rtas.bin slof.bin skiboot.lid \
palcode-clipper \ palcode-clipper \

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@ -37,7 +37,7 @@ Wa = -Wa,
ASFLAGS += -32 ASFLAGS += -32
QEMU_CFLAGS += $(call cc-c-option, $(QEMU_CFLAGS), $(Wa)-32) QEMU_CFLAGS += $(call cc-c-option, $(QEMU_CFLAGS), $(Wa)-32)
build-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin build-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin pvh.bin
# suppress auto-removal of intermediate files # suppress auto-removal of intermediate files
.SECONDARY: .SECONDARY:
@ -46,6 +46,9 @@ build-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin
%.o: %.S %.o: %.S
$(call quiet-command,$(CPP) $(QEMU_INCLUDES) $(QEMU_DGFLAGS) -c -o - $< | $(AS) $(ASFLAGS) -o $@,"AS","$(TARGET_DIR)$@") $(call quiet-command,$(CPP) $(QEMU_INCLUDES) $(QEMU_DGFLAGS) -c -o - $< | $(AS) $(ASFLAGS) -o $@,"AS","$(TARGET_DIR)$@")
pvh.img: pvh.o pvh_main.o
$(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m $(LD_I386_EMULATION) -T $(SRC_PATH)/pc-bios/optionrom/flat.lds -s -o $@ $^,"BUILD","$(TARGET_DIR)$@")
%.img: %.o %.img: %.o
$(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m $(LD_I386_EMULATION) -T $(SRC_PATH)/pc-bios/optionrom/flat.lds -s -o $@ $<,"BUILD","$(TARGET_DIR)$@") $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m $(LD_I386_EMULATION) -T $(SRC_PATH)/pc-bios/optionrom/flat.lds -s -o $@ $<,"BUILD","$(TARGET_DIR)$@")

200
pc-bios/optionrom/pvh.S Normal file
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@ -0,0 +1,200 @@
/*
* PVH Option ROM
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Copyright Novell Inc, 2009
* Authors: Alexander Graf <agraf@suse.de>
*
* Copyright (c) 2019 Red Hat Inc.
* Authors: Stefano Garzarella <sgarzare@redhat.com>
*/
#include "optionrom.h"
#define BOOT_ROM_PRODUCT "PVH loader"
#define GS_PROT_JUMP 0
#define GS_GDT_DESC 6
#ifdef OPTION_ROM_START
#undef OPTION_ROM_START
#endif
#ifdef OPTION_ROM_END
#undef OPTION_ROM_END
#endif
/*
* Redefine OPTION_ROM_START and OPTION_ROM_END, because this rom is produced
* linking multiple objects.
* signrom.py will add padding.
*/
#define OPTION_ROM_START \
.code16; \
.text; \
.global _start; \
_start:; \
.short 0xaa55; \
.byte 3; /* desired size in 512 units */
#define OPTION_ROM_END \
_end:
BOOT_ROM_START
run_pvhboot:
cli
cld
mov %cs, %eax
shl $0x4, %eax
/* set up a long jump descriptor that is PC relative */
/* move stack memory to %gs */
mov %ss, %ecx
shl $0x4, %ecx
mov %esp, %ebx
add %ebx, %ecx
sub $0x20, %ecx
sub $0x30, %esp
shr $0x4, %ecx
mov %cx, %gs
/* now push the indirect jump descriptor there */
mov (prot_jump), %ebx
add %eax, %ebx
movl %ebx, %gs:GS_PROT_JUMP
mov $8, %bx
movw %bx, %gs:GS_PROT_JUMP + 4
/* fix the gdt descriptor to be PC relative */
movw (gdt_desc), %bx
movw %bx, %gs:GS_GDT_DESC
movl (gdt_desc+2), %ebx
add %eax, %ebx
movl %ebx, %gs:GS_GDT_DESC + 2
/* initialize HVM memmap table using int 0x15(e820) */
/* ES = pvh_e820 struct */
mov $pvh_e820, %eax
shr $4, %eax
mov %ax, %es
/* start storing memmap table at %es:8 (pvh_e820.table) */
mov $8,%edi
xor %ebx, %ebx
jmp memmap_loop
memmap_loop_check:
/* pvh_e820 can contains up to 128 entries */
cmp $128, %ebx
je memmap_done
memmap_loop:
/* entry size (hvm_memmap_table_entry) & max buffer size (int15) */
movl $24, %ecx
/* e820 */
movl $0x0000e820, %eax
/* 'SMAP' magic */
movl $0x534d4150, %edx
/* store counter value at %es:0 (pvh_e820.entries) */
movl %ebx, %es:0
int $0x15
/* error or last entry already done? */
jb memmap_err
/* %edi += entry size (hvm_memmap_table_entry) */
add $24, %edi
/* continuation value 0 means last entry */
test %ebx, %ebx
jnz memmap_loop_check
/* increase pvh_e820.entries to save the last entry */
movl %es:0, %ebx
inc %ebx
memmap_done:
movl %ebx, %es:0
memmap_err:
/* load the GDT before going into protected mode */
lgdt:
data32 lgdt %gs:GS_GDT_DESC
/* get us to protected mode now */
movl $1, %eax
movl %eax, %cr0
/* the LJMP sets CS for us and gets us to 32-bit */
ljmp:
data32 ljmp *%gs:GS_PROT_JUMP
prot_mode:
.code32
/* initialize all other segments */
movl $0x10, %eax
movl %eax, %ss
movl %eax, %ds
movl %eax, %es
movl %eax, %fs
movl %eax, %gs
jmp pvh_load_kernel
/* Variables */
.align 4, 0
prot_jump: .long prot_mode
.short 8
.align 4, 0
gdt:
/* 0x00 */
.byte 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
/*
* 0x08: code segment
* (base=0, limit=0xfffff, type=32bit code exec/read, DPL=0, 4k)
*/
.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x9a, 0xcf, 0x00
/*
* 0x10: data segment
* (base=0, limit=0xfffff, type=32bit data read/write, DPL=0, 4k)
*/
.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x92, 0xcf, 0x00
/*
* 0x18: code segment
* (base=0, limit=0x0ffff, type=16bit code exec/read/conf, DPL=0, 1b)
*/
.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x9e, 0x00, 0x00
/*
* 0x20: data segment
* (base=0, limit=0x0ffff, type=16bit data read/write, DPL=0, 1b)
*/
.byte 0xff, 0xff, 0x00, 0x00, 0x00, 0x92, 0x00, 0x00
gdt_desc:
.short (5 * 8) - 1
.long gdt
BOOT_ROM_END

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@ -0,0 +1,116 @@
/*
* PVH Option ROM for fw_cfg DMA
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Copyright (c) 2019 Red Hat Inc.
* Authors:
* Stefano Garzarella <sgarzare@redhat.com>
*/
asm (".code32"); /* this code will be executed in protected mode */
#include <stddef.h>
#include <stdint.h>
#include "optrom.h"
#include "optrom_fw_cfg.h"
#include "../../include/hw/xen/start_info.h"
#define RSDP_SIGNATURE 0x2052545020445352LL /* "RSD PTR " */
#define RSDP_AREA_ADDR 0x000E0000
#define RSDP_AREA_SIZE 2048
#define EBDA_BASE_ADDR 0x0000040E
#define EBDA_SIZE 1024
#define E820_MAXENTRIES 128
#define CMDLINE_BUFSIZE 4096
/* e820 table filled in pvh.S using int 0x15 */
struct pvh_e820_table {
uint32_t entries;
uint32_t reserved;
struct hvm_memmap_table_entry table[E820_MAXENTRIES];
};
struct pvh_e820_table pvh_e820 asm("pvh_e820") __attribute__ ((aligned));
static struct hvm_start_info start_info;
static uint8_t cmdline_buffer[CMDLINE_BUFSIZE];
/* Search RSDP signature. */
static uintptr_t search_rsdp(uint32_t start_addr, uint32_t end_addr)
{
uint64_t *rsdp_p;
/* RSDP signature is always on a 16 byte boundary */
for (rsdp_p = (uint64_t *)start_addr; rsdp_p < (uint64_t *)end_addr;
rsdp_p += 2) {
if (*rsdp_p == RSDP_SIGNATURE) {
return (uintptr_t)rsdp_p;
}
}
return 0;
}
/* Force the asm name without leading underscore, even on Win32. */
extern void pvh_load_kernel(void) asm("pvh_load_kernel");
void pvh_load_kernel(void)
{
void *cmdline_addr = &cmdline_buffer;
void *kernel_entry;
uint32_t cmdline_size, fw_cfg_version = bios_cfg_version();
start_info.magic = XEN_HVM_START_MAGIC_VALUE;
start_info.version = 1;
/*
* pvh_e820 is filled in the pvh.S before to switch in protected mode,
* because we can use int 0x15 only in real mode.
*/
start_info.memmap_entries = pvh_e820.entries;
start_info.memmap_paddr = (uintptr_t)pvh_e820.table;
/*
* Search RSDP in the main BIOS area below 1 MB.
* SeaBIOS store the RSDP in this area, so we try it first.
*/
start_info.rsdp_paddr = search_rsdp(RSDP_AREA_ADDR,
RSDP_AREA_ADDR + RSDP_AREA_SIZE);
/* Search RSDP in the EBDA if it is not found */
if (!start_info.rsdp_paddr) {
/*
* Th EBDA address is stored at EBDA_BASE_ADDR. It contains 2 bytes
* segment pointer to EBDA, so we must convert it to a linear address.
*/
uint32_t ebda_paddr = ((uint32_t)*((uint16_t *)EBDA_BASE_ADDR)) << 4;
if (ebda_paddr > 0x400) {
uint32_t *ebda = (uint32_t *)ebda_paddr;
start_info.rsdp_paddr = search_rsdp(*ebda, *ebda + EBDA_SIZE);
}
}
bios_cfg_read_entry(&cmdline_size, FW_CFG_CMDLINE_SIZE, 4, fw_cfg_version);
bios_cfg_read_entry(cmdline_addr, FW_CFG_CMDLINE_DATA, cmdline_size,
fw_cfg_version);
start_info.cmdline_paddr = (uintptr_t)cmdline_addr;
bios_cfg_read_entry(&kernel_entry, FW_CFG_KERNEL_ENTRY, 4, fw_cfg_version);
asm volatile("jmp *%1" : : "b"(&start_info), "c"(kernel_entry));
}

BIN
pc-bios/pvh.bin Normal file

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