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 <sgarz...@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
---
pc-bios/optionrom/Makefile | 5 +-
pc-bios/optionrom/pvh.S | 200 +++++++++++++++++++++++++++++++++++
pc-bios/optionrom/pvh_main.c | 117 ++++++++++++++++++++
3 files changed, 321 insertions(+), 1 deletion(-)
create mode 100644 pc-bios/optionrom/pvh.S
create mode 100644 pc-bios/optionrom/pvh_main.c
diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
index a9a9e5e7eb..92c91d9949 100644
--- a/pc-bios/optionrom/Makefile
+++ b/pc-bios/optionrom/Makefile
@@ -37,7 +37,7 @@ Wa = -Wa,
ASFLAGS += -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
.SECONDARY:
@@ -46,6 +46,9 @@ build-all: multiboot.bin linuxboot.bin linuxboot_dma.bin
kvmvapic.bin
%.o: %.S
$(call quiet-command,$(CPP) $(QEMU_INCLUDES) $(QEMU_DGFLAGS) -c -o - $< | $(AS) $(ASFLAGS)
-o $@,"AS","$(TARGET_DIR)$@")
+%.img: %.o %_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
$(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m $(LD_I386_EMULATION) -T
$(SRC_PATH)/pc-bios/optionrom/flat.lds -s -o $@ $<,"BUILD","$(TARGET_DIR)$@")
diff --git a/pc-bios/optionrom/pvh.S b/pc-bios/optionrom/pvh.S
new file mode 100644
index 0000000000..e1d7f4a7a7
--- /dev/null
+++ b/pc-bios/optionrom/pvh.S
@@ -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 <ag...@suse.de>
+ *
+ * Copyright (c) 2019 Red Hat Inc.
+ * Authors: Stefano Garzarella <sgarz...@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
diff --git a/pc-bios/optionrom/pvh_main.c b/pc-bios/optionrom/pvh_main.c
new file mode 100644
index 0000000000..9100952463
--- /dev/null
+++ b/pc-bios/optionrom/pvh_main.c
@@ -0,0 +1,117 @@
+/*
+ * 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 <sgarz...@redhat.com>
+ */
+
+asm (".code32"); /* this code will be executed in protect mode */
