On 11/05/2016 23:06, Richard W.M. Jones wrote:
> From: Marc Marí <mar...@redhat.com>
>
> This optionrom is based on linuxboot.S.
>
> Signed-off-by: Marc Marí <mar...@redhat.com>
> Signed-off-by: Richard W.M. Jones <rjo...@redhat.com>
Hmm, I hadn't noticed that you added -m16. That breaks on even
not-too-old GCC (such as 4.8 on RHEL/CentOS 7). Can you add some
Makefile logic to switch between "-m16" and a "-include code16gcc.h"
that only contains 'asm(".code16gcc");'?
Also, you need to add linuxboot_dma.bin after linuxboot.bin in the
main Makefile.
Thanks,
Paolo
> ---
> .gitignore | 4 +
> hw/i386/pc.c | 10 +-
> hw/nvram/fw_cfg.c | 2 +-
> include/hw/nvram/fw_cfg.h | 1 +
> pc-bios/optionrom/Makefile | 13 +-
> pc-bios/optionrom/linuxboot_dma.c | 291
> ++++++++++++++++++++++++++++++++++++++
> 6 files changed, 316 insertions(+), 5 deletions(-)
> create mode 100644 pc-bios/optionrom/linuxboot_dma.c
>
> diff --git a/.gitignore b/.gitignore
> index 88a80ff..101d1e0 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -94,6 +94,10 @@
> /pc-bios/optionrom/linuxboot.bin
> /pc-bios/optionrom/linuxboot.raw
> /pc-bios/optionrom/linuxboot.img
> +/pc-bios/optionrom/linuxboot_dma.asm
> +/pc-bios/optionrom/linuxboot_dma.bin
> +/pc-bios/optionrom/linuxboot_dma.raw
> +/pc-bios/optionrom/linuxboot_dma.img
> /pc-bios/optionrom/multiboot.asm
> /pc-bios/optionrom/multiboot.bin
> /pc-bios/optionrom/multiboot.raw
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 99437e0..098d571 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -999,8 +999,13 @@ static void load_linux(PCMachineState *pcms,
> fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size);
> fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size);
>
> - option_rom[nb_option_roms].name = "linuxboot.bin";
> - option_rom[nb_option_roms].bootindex = 0;
> + if (fw_cfg_dma_enabled(fw_cfg)) {
> + option_rom[nb_option_roms].name = "linuxboot_dma.bin";
> + option_rom[nb_option_roms].bootindex = 0;
> + } else {
> + option_rom[nb_option_roms].name = "linuxboot.bin";
> + option_rom[nb_option_roms].bootindex = 0;
> + }
> nb_option_roms++;
> }
>
> @@ -1263,6 +1268,7 @@ void xen_load_linux(PCMachineState *pcms)
> load_linux(pcms, fw_cfg);
> for (i = 0; i < nb_option_roms; i++) {
> assert(!strcmp(option_rom[i].name, "linuxboot.bin") ||
> + !strcmp(option_rom[i].name, "linuxboot_dma.bin") ||
> !strcmp(option_rom[i].name, "multiboot.bin"));
> rom_add_option(option_rom[i].name, option_rom[i].bootindex);
> }
> diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
> index 999f480..114aea8 100644
> --- a/hw/nvram/fw_cfg.c
> +++ b/hw/nvram/fw_cfg.c
> @@ -551,7 +551,7 @@ static bool is_version_1(void *opaque, int version_id)
> return version_id == 1;
> }
>
> -static bool fw_cfg_dma_enabled(void *opaque)
> +bool fw_cfg_dma_enabled(void *opaque)
> {
> FWCfgState *s = opaque;
>
> diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
> index d008112..5c27a1f 100644
> --- a/include/hw/nvram/fw_cfg.h
> +++ b/include/hw/nvram/fw_cfg.h
> @@ -182,5 +182,6 @@ FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr,
> hwaddr dma_addr, AddressSpace *dma_as);
>
> FWCfgState *fw_cfg_find(void);
> +bool fw_cfg_dma_enabled(void *opaque);
>
> #endif
> diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
> index ce4852a..a51dd6e 100644
> --- a/pc-bios/optionrom/Makefile
> +++ b/pc-bios/optionrom/Makefile
> @@ -13,15 +13,24 @@ CFLAGS := -Wall -Wstrict-prototypes -Werror
> -fomit-frame-pointer -fno-builtin
> CFLAGS += -I$(SRC_PATH)
> CFLAGS += $(call cc-option, $(CFLAGS), -fno-stack-protector)
> CFLAGS += $(CFLAGS_NOPIE)
> +CFLAGS += -m16
> QEMU_CFLAGS = $(CFLAGS)
>
> -build-all: multiboot.bin linuxboot.bin kvmvapic.bin
> +ASFLAGS += -32
> +
> +build-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin
>
> # suppress auto-removal of intermediate files
> .SECONDARY:
>
> +ifdef CONFIG_WIN32
> +LD_EMULATION = i386pe
> +else
> +LD_EMULATION = elf_i386
> +endif
> +
> %.img: %.o
> - $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e _start -s -o $@
> $<," Building $(TARGET_DIR)$@")
> + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m $(LD_EMULATION) -Ttext 0
> -e _start -s -o $@ $<," Building $(TARGET_DIR)$@")
>
> %.raw: %.img
> $(call quiet-command,$(OBJCOPY) -O binary -j .text $< $@," Building
> $(TARGET_DIR)$@")
> diff --git a/pc-bios/optionrom/linuxboot_dma.c
> b/pc-bios/optionrom/linuxboot_dma.c
> new file mode 100644
> index 0000000..8ebc480
> --- /dev/null
> +++ b/pc-bios/optionrom/linuxboot_dma.c
> @@ -0,0 +1,291 @@
> +/*
> + * Linux Boot 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) 2015-2016 Red Hat Inc.
> + * Authors:
> + * Marc Marí <mar...@redhat.com>
> + * Richard W.M. Jones <rjo...@redhat.com>
> + */
> +
> +asm(
> +".text\n"
> +".global _start\n"
> +"_start:\n"
> +" .short 0xaa55\n"
> +" .byte 0\n" /* size in 512 units, filled in by signrom.py */
> +" .byte 0xcb\n" /* far return without prefix */
> +" .org 0x18\n"
> +" .short 0\n"
> +" .short _pnph\n"
> +"_pnph:\n"
> +" .ascii \"$PnP\"\n"
> +" .byte 0x01\n"
> +" .byte (_pnph_len / 16)\n"
> +" .short 0x0000\n"
> +" .byte 0x00\n"
> +" .byte 0x00\n"
> +" .long 0x00000000\n"
> +" .short _manufacturer\n"
> +" .short _product\n"
> +" .long 0x00000000\n"
> +" .short 0x0000\n"
> +" .short 0x0000\n"
> +" .short _bev\n"
> +" .short 0x0000\n"
> +" .short 0x0000\n"
> +" .equ _pnph_len, . - _pnph\n"
> +"_manufacturer:\n"
> +" .asciz \"QEMU\"\n"
> +"_product:\n"
> +" .asciz \"Linux loader DMA\"\n"
> +" .align 4, 0\n"
> +"_bev:\n"
> +" cli\n"
> +" cld\n"
> +" jmp load_kernel\n"
> +);
> +
> +#include "../../include/hw/nvram/fw_cfg_keys.h"
> +
> +/* QEMU_CFG_DMA_CONTROL bits */
> +#define BIOS_CFG_DMA_CTL_ERROR 0x01
> +#define BIOS_CFG_DMA_CTL_READ 0x02
> +#define BIOS_CFG_DMA_CTL_SKIP 0x04
> +#define BIOS_CFG_DMA_CTL_SELECT 0x08
> +
> +#define BIOS_CFG_DMA_ADDR_HIGH 0x514
> +#define BIOS_CFG_DMA_ADDR_LOW 0x518
> +
> +#define uint64_t unsigned long long
> +#define uint32_t unsigned int
> +#define uint16_t unsigned short
> +
> +#define barrier() asm("" : : : "memory")
> +
> +typedef struct FWCfgDmaAccess {
> + uint32_t control;
> + uint32_t length;
> + uint64_t address;
> +} __attribute__((packed)) FWCfgDmaAccess;
> +
> +static inline void outl(uint32_t value, uint16_t port)
> +{
> + asm("outl %0, %w1" : : "a"(value), "Nd"(port));
> +}
> +
> +static inline void set_es(void *addr)
> +{
> + uint32_t seg = (uint32_t)addr >> 4;
> + asm("movl %0, %%es" : : "r"(seg));
> +}
> +
> +#ifdef __clang__
> +#define ADDR32
> +#else
> +#define ADDR32 "addr32 "
> +#endif
> +
> +static inline uint16_t readw_es(uint16_t offset)
> +{
> + uint16_t val;
> + asm(ADDR32 "movw %%es:(%1), %0" : "=r"(val) : "r"((uint32_t)offset));
> + barrier();
> + return val;
> +}
> +
> +static inline uint32_t readl_es(uint16_t offset)
> +{
> + uint32_t val;
> + asm(ADDR32 "movl %%es:(%1), %0" : "=r"(val) : "r"((uint32_t)offset));
> + barrier();
> + return val;
> +}
> +
> +static inline void writel_es(uint16_t offset, uint32_t val)
> +{
> + barrier();
> + asm(ADDR32 "movl %0, %%es:(%1)" : : "r"(val), "r"((uint32_t)offset));
> +}
> +
> +static inline uint32_t bswap32(uint32_t x)
> +{
> + return
> + ((x & 0x000000ffU) << 24) |
> + ((x & 0x0000ff00U) << 8) |
> + ((x & 0x00ff0000U) >> 8) |
> + ((x & 0xff000000U) >> 24);
> +}
> +
> +static inline uint64_t bswap64(uint64_t x)
> +{
> + return
> + ((x & 0x00000000000000ffULL) << 56) |
> + ((x & 0x000000000000ff00ULL) << 40) |
> + ((x & 0x0000000000ff0000ULL) << 24) |
> + ((x & 0x00000000ff000000ULL) << 8) |
> + ((x & 0x000000ff00000000ULL) >> 8) |
> + ((x & 0x0000ff0000000000ULL) >> 24) |
> + ((x & 0x00ff000000000000ULL) >> 40) |
> + ((x & 0xff00000000000000ULL) >> 56);
> +}
> +
> +static inline uint64_t cpu_to_be64(uint64_t x)
> +{
> + return bswap64(x);
> +}
> +
> +static inline uint32_t cpu_to_be32(uint32_t x)
> +{
> + return bswap32(x);
> +}
> +
> +static inline uint32_t be32_to_cpu(uint32_t x)
> +{
> + return bswap32(x);
> +}
> +
> +static void bios_cfg_read_entry(void *buf, uint16_t entry, uint32_t len)
> +{
> + FWCfgDmaAccess access;
> + uint32_t control = (entry << 16) | BIOS_CFG_DMA_CTL_SELECT
> + | BIOS_CFG_DMA_CTL_READ;
> +
> + access.address = cpu_to_be64((uint64_t)(uint32_t)buf);
> + access.length = cpu_to_be32(len);
> + access.control = cpu_to_be32(control);
> +
> + barrier();
> +
> + outl(cpu_to_be32((uint32_t)&access), BIOS_CFG_DMA_ADDR_LOW);
> +
> + while (be32_to_cpu(access.control) & ~BIOS_CFG_DMA_CTL_ERROR) {
> + barrier();
> + }
> +}
> +
> +/* Return top of memory using BIOS function E801. */
> +static uint32_t get_e801_addr(void)
> +{
> + uint16_t ax, bx, cx, dx;
> + uint32_t ret;
> +
> + asm("int $0x15\n"
> + : "=a"(ax), "=b"(bx), "=c"(cx), "=d"(dx)
> + : "a"(0xe801), "b"(0), "c"(0), "d"(0));
> +
> + /* Not SeaBIOS, but in theory a BIOS could return CX=DX=0 in which
> + * case we need to use the result from AX & BX instead.
> + */
> + if (cx == 0 && dx == 0) {
> + cx = ax;
> + dx = bx;
> + }
> +
> + if (dx) {
> + /* DX = extended memory above 16M, in 64K units.
> + * Convert it to bytes and return.
> + */
> + ret = ((uint32_t)dx + 256 /* 16M in 64K units */) << 16;
> + } else {
> + /* This is a fallback path for machines with <= 16MB of RAM,
> + * which probably would never be the case, but deal with it
> + * anyway.
> + *
> + * CX = extended memory between 1M and 16M, in kilobytes
> + * Convert it to bytes and return.
> + */
> + ret = ((uint32_t)cx + 1024 /* 1M in K */) << 10;
> + }
> +
> + return ret;
> +}
> +
> +void load_kernel(void)
> +{
> + void *setup_addr;
> + void *initrd_addr;
> + void *kernel_addr;
> + void *cmdline_addr;
> + uint32_t setup_size;
> + uint32_t initrd_size;
> + uint32_t kernel_size;
> + uint32_t cmdline_size;
> + uint32_t initrd_end_page, max_allowed_page;
> + uint32_t segment_addr, stack_addr;
> +
> + bios_cfg_read_entry(&setup_addr, FW_CFG_SETUP_ADDR, 4);
> + bios_cfg_read_entry(&setup_size, FW_CFG_SETUP_SIZE, 4);
> + bios_cfg_read_entry(setup_addr, FW_CFG_SETUP_DATA, setup_size);
> +
> + set_es(setup_addr);
> +
> + /* For protocol < 0x203 we don't have initrd_max ... */
> + if (readw_es(0x206) < 0x203) {
> + /* ... so we assume initrd_max = 0x37ffffff. */
> + writel_es(0x22c, 0x37ffffff);
> + }
> +
> + bios_cfg_read_entry(&initrd_addr, FW_CFG_INITRD_ADDR, 4);
> + bios_cfg_read_entry(&initrd_size, FW_CFG_INITRD_SIZE, 4);
> +
> + initrd_end_page = ((uint32_t)(initrd_addr + initrd_size) & -4096);
> + max_allowed_page = (readl_es(0x22c) & -4096);
> +
> + if (initrd_end_page != 0 && max_allowed_page != 0 &&
> + initrd_end_page != max_allowed_page) {
> + /* Initrd at the end of memory. Compute better initrd address
> + * based on e801 data
> + */
> + initrd_addr = (void *)((get_e801_addr() - initrd_size) & -4096);
> + writel_es(0x218, (uint32_t)initrd_addr);
> +
> + }
> +
> + bios_cfg_read_entry(initrd_addr, FW_CFG_INITRD_DATA, initrd_size);
> +
> + bios_cfg_read_entry(&kernel_addr, FW_CFG_KERNEL_ADDR, 4);
> + bios_cfg_read_entry(&kernel_size, FW_CFG_KERNEL_SIZE, 4);
> + bios_cfg_read_entry(kernel_addr, FW_CFG_KERNEL_DATA, kernel_size);
> +
> + bios_cfg_read_entry(&cmdline_addr, FW_CFG_CMDLINE_ADDR, 4);
> + bios_cfg_read_entry(&cmdline_size, FW_CFG_CMDLINE_SIZE, 4);
> + bios_cfg_read_entry(cmdline_addr, FW_CFG_CMDLINE_DATA, cmdline_size);
> +
> + /* Boot linux */
> + segment_addr = ((uint32_t)setup_addr >> 4);
> + stack_addr = (uint32_t)(cmdline_addr - setup_addr - 16);
> +
> + /* As we are changing critical registers, we cannot leave freedom to the
> + * compiler.
> + */
> + asm("movw %%ax, %%ds\n"
> + "movw %%ax, %%es\n"
> + "movw %%ax, %%fs\n"
> + "movw %%ax, %%gs\n"
> + "movw %%ax, %%ss\n"
> + "movl %%ebx, %%esp\n"
> + "addw $0x20, %%ax\n"
> + "pushw %%ax\n" /* CS */
> + "pushw $0\n" /* IP */
> + /* Clear registers and jump to Linux */
> + "xor %%ebx, %%ebx\n"
> + "xor %%ecx, %%ecx\n"
> + "xor %%edx, %%edx\n"
> + "xor %%edi, %%edi\n"
> + "xor %%ebp, %%ebp\n"
> + "lretw\n"
> + : : "a"(segment_addr), "b"(stack_addr));
> +}
>
