Message ID | 1453727868-11147-1-git-send-email-markmb@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí wrote: > +linuxboot_dma.img: linuxboot_dma.o > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m elf_i386 -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") > + > %.img: %.o > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") Why is -m elf_i386 necessary for linuxboot_dma.img but not for the other *.img files? Otherwise: Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
On Tue, 26 Jan 2016 11:11:54 +0000 Stefan Hajnoczi <stefanha@redhat.com> wrote: > On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí wrote: > > +linuxboot_dma.img: linuxboot_dma.o > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m elf_i386 > > -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") + > > %.img: %.o > > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e > > _start -s -o $@ $<," Building $(TARGET_DIR)$@") > > Why is -m elf_i386 necessary for linuxboot_dma.img but not for the > other *.img files? I cannot give a precise explanation. But if I don't force an output type, I get this error: Building optionrom/linuxboot_dma.img ld: i386 architecture of input file `linuxboot_dma.o' is incompatible with i386:x86-64 output Marc
On Di, 2016-01-26 at 12:20 +0100, Marc Marí wrote: > On Tue, 26 Jan 2016 11:11:54 +0000 > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí wrote: > > > +linuxboot_dma.img: linuxboot_dma.o > > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m elf_i386 > > > -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") + > > > %.img: %.o > > > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e > > > _start -s -o $@ $<," Building $(TARGET_DIR)$@") > > > > Why is -m elf_i386 necessary for linuxboot_dma.img but not for the > > other *.img files? > > I cannot give a precise explanation. But if I don't force an output > type, I get this error: > > Building optionrom/linuxboot_dma.img > ld: i386 architecture of input file `linuxboot_dma.o' is incompatible > with i386:x86-64 output Any chance the linker needs -m32 too? cheers, Gerd
On Tue, Jan 26, 2016 at 12:26:12PM +0100, Gerd Hoffmann wrote: > On Di, 2016-01-26 at 12:20 +0100, Marc Marí wrote: > > On Tue, 26 Jan 2016 11:11:54 +0000 > > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí wrote: > > > > +linuxboot_dma.img: linuxboot_dma.o > > > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m elf_i386 > > > > -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") + > > > > %.img: %.o > > > > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e > > > > _start -s -o $@ $<," Building $(TARGET_DIR)$@") > > > > > > Why is -m elf_i386 necessary for linuxboot_dma.img but not for the > > > other *.img files? > > > > I cannot give a precise explanation. But if I don't force an output > > type, I get this error: > > > > Building optionrom/linuxboot_dma.img > > ld: i386 architecture of input file `linuxboot_dma.o' is incompatible > > with i386:x86-64 output > > Any chance the linker needs -m32 too? I wonder why this isn't a problem for the existing firmware code. Are we really building x86_64 ELF files for our firmware? Stefan
On Wed, 27 Jan 2016 16:43:29 +0000 Stefan Hajnoczi <stefanha@redhat.com> wrote: > On Tue, Jan 26, 2016 at 12:26:12PM +0100, Gerd Hoffmann wrote: > > On Di, 2016-01-26 at 12:20 +0100, Marc Marí wrote: > > > On Tue, 26 Jan 2016 11:11:54 +0000 > > > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > > > On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí wrote: > > > > > +linuxboot_dma.img: linuxboot_dma.o > > > > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m > > > > > elf_i386 -Ttext 0 -e _start -s -o $@ $<," Building > > > > > $(TARGET_DIR)$@") + %.img: %.o > > > > > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 > > > > > -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") > > > > > > > > Why is -m elf_i386 necessary for linuxboot_dma.img but not for > > > > the other *.img files? > > > > > > I cannot give a precise explanation. But if I don't force an > > > output type, I get this error: > > > > > > Building optionrom/linuxboot_dma.img > > > ld: i386 architecture of input file `linuxboot_dma.o' is > > > incompatible with i386:x86-64 output > > > > Any chance the linker needs -m32 too? > > I wonder why this isn't a problem for the existing firmware code. Are > we really building x86_64 ELF files for our firmware? Yes they are x86_64: pc-bios/optionrom/linuxboot.img: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, stripped But as they are written directly in assembly, it does not give any problem. Whereas when mixing C and ASM, it does give problems. Marc
On Wed, Jan 27, 2016 at 05:57:28PM +0100, Marc Marí wrote: > On Wed, 27 Jan 2016 16:43:29 +0000 > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > On Tue, Jan 26, 2016 at 12:26:12PM +0100, Gerd Hoffmann wrote: > > > On Di, 2016-01-26 at 12:20 +0100, Marc Marí wrote: > > > > On Tue, 26 Jan 2016 11:11:54 +0000 > > > > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > > > > > On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí wrote: > > > > > > +linuxboot_dma.img: linuxboot_dma.o > > > > > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m > > > > > > elf_i386 -Ttext 0 -e _start -s -o $@ $<," Building > > > > > > $(TARGET_DIR)$@") + %.img: %.o > > > > > > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 > > > > > > -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") > > > > > > > > > > Why is -m elf_i386 necessary for linuxboot_dma.img but not for > > > > > the other *.img files? > > > > > > > > I cannot give a precise explanation. But if I don't force an > > > > output type, I get this error: > > > > > > > > Building optionrom/linuxboot_dma.img > > > > ld: i386 architecture of input file `linuxboot_dma.o' is > > > > incompatible with i386:x86-64 output > > > > > > Any chance the linker needs -m32 too? > > > > I wonder why this isn't a problem for the existing firmware code. Are > > we really building x86_64 ELF files for our firmware? > > Yes they are x86_64: > > pc-bios/optionrom/linuxboot.img: ELF 64-bit LSB executable, x86-64, > version 1 (SYSV), statically linked, stripped > > But as they are written directly in assembly, it does not give any > problem. Whereas when mixing C and ASM, it does give problems. Would it hurt anything to add "-m elf_i386" to the generic assembler rule and then use that for both targets? (Just to keep the makefile a little simpler.) -Kevin
On Wed, 27 Jan 2016 12:17:27 -0500 "Kevin O'Connor" <kevin@koconnor.net> wrote: > On Wed, Jan 27, 2016 at 05:57:28PM +0100, Marc Marí wrote: > > On Wed, 27 Jan 2016 16:43:29 +0000 > > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > On Tue, Jan 26, 2016 at 12:26:12PM +0100, Gerd Hoffmann wrote: > > > > On Di, 2016-01-26 at 12:20 +0100, Marc Marí wrote: > > > > > On Tue, 26 Jan 2016 11:11:54 +0000 > > > > > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > > > > > > > On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí > > > > > > wrote: > > > > > > > +linuxboot_dma.img: linuxboot_dma.o > > > > > > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m > > > > > > > elf_i386 -Ttext 0 -e _start -s -o $@ $<," Building > > > > > > > $(TARGET_DIR)$@") + %.img: %.o > > > > > > > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) > > > > > > > -Ttext 0 -e _start -s -o $@ $<," Building > > > > > > > $(TARGET_DIR)$@") > > > > > > > > > > > > Why is -m elf_i386 necessary for linuxboot_dma.img but not > > > > > > for the other *.img files? > > > > > > > > > > I cannot give a precise explanation. But if I don't force an > > > > > output type, I get this error: > > > > > > > > > > Building optionrom/linuxboot_dma.img > > > > > ld: i386 architecture of input file `linuxboot_dma.o' is > > > > > incompatible with i386:x86-64 output > > > > > > > > Any chance the linker needs -m32 too? > > > > > > I wonder why this isn't a problem for the existing firmware > > > code. Are we really building x86_64 ELF files for our firmware? > > > > Yes they are x86_64: > > > > pc-bios/optionrom/linuxboot.img: ELF 64-bit LSB executable, x86-64, > > version 1 (SYSV), statically linked, stripped > > > > But as they are written directly in assembly, it does not give any > > problem. Whereas when mixing C and ASM, it does give problems. > > Would it hurt anything to add "-m elf_i386" to the generic assembler > rule and then use that for both targets? (Just to keep the makefile a > little simpler.) It doesn't seem to hurt, and it is simpler. Marc
On Thu, Jan 28, 2016 at 11:18:07AM +0100, Marc Marí wrote: > On Wed, 27 Jan 2016 12:17:27 -0500 > "Kevin O'Connor" <kevin@koconnor.net> wrote: > > > On Wed, Jan 27, 2016 at 05:57:28PM +0100, Marc Marí wrote: > > > On Wed, 27 Jan 2016 16:43:29 +0000 > > > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > > > On Tue, Jan 26, 2016 at 12:26:12PM +0100, Gerd Hoffmann wrote: > > > > > On Di, 2016-01-26 at 12:20 +0100, Marc Marí wrote: > > > > > > On Tue, 26 Jan 2016 11:11:54 +0000 > > > > > > Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > > > > > > > > > On Mon, Jan 25, 2016 at 02:17:48PM +0100, Marc Marí > > > > > > > wrote: > > > > > > > > +linuxboot_dma.img: linuxboot_dma.o > > > > > > > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m > > > > > > > > elf_i386 -Ttext 0 -e _start -s -o $@ $<," Building > > > > > > > > $(TARGET_DIR)$@") + %.img: %.o > > > > > > > > $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) > > > > > > > > -Ttext 0 -e _start -s -o $@ $<," Building > > > > > > > > $(TARGET_DIR)$@") > > > > > > > > > > > > > > Why is -m elf_i386 necessary for linuxboot_dma.img but not > > > > > > > for the other *.img files? > > > > > > > > > > > > I cannot give a precise explanation. But if I don't force an > > > > > > output type, I get this error: > > > > > > > > > > > > Building optionrom/linuxboot_dma.img > > > > > > ld: i386 architecture of input file `linuxboot_dma.o' is > > > > > > incompatible with i386:x86-64 output > > > > > > > > > > Any chance the linker needs -m32 too? > > > > > > > > I wonder why this isn't a problem for the existing firmware > > > > code. Are we really building x86_64 ELF files for our firmware? > > > > > > Yes they are x86_64: > > > > > > pc-bios/optionrom/linuxboot.img: ELF 64-bit LSB executable, x86-64, > > > version 1 (SYSV), statically linked, stripped > > > > > > But as they are written directly in assembly, it does not give any > > > problem. Whereas when mixing C and ASM, it does give problems. > > > > Would it hurt anything to add "-m elf_i386" to the generic assembler > > rule and then use that for both targets? (Just to keep the makefile a > > little simpler.) > > It doesn't seem to hurt, and it is simpler. Great, I think this makes sense. Stefan
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 459260b..00339fa 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1007,8 +1007,13 @@ 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++; } diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index a1d650d..d0a5753 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -546,7 +546,7 @@ 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 664eaf6..953e58d 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -219,6 +219,7 @@ 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 /* NO_QEMU_PROTOS */ diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile index ce4852a..8c769ef 100644 --- a/pc-bios/optionrom/Makefile +++ b/pc-bios/optionrom/Makefile @@ -13,13 +13,17 @@ 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 += -m32 QEMU_CFLAGS = $(CFLAGS) -build-all: multiboot.bin linuxboot.bin kvmvapic.bin +build-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bin # suppress auto-removal of intermediate files .SECONDARY: +linuxboot_dma.img: linuxboot_dma.o + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m elf_i386 -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") + %.img: %.o $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e _start -s -o $@ $<," 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..43594c2 --- /dev/null +++ b/pc-bios/optionrom/linuxboot_dma.c @@ -0,0 +1,262 @@ +/* + * 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 Red Hat Inc. + * Authors: Marc Marí <markmb@redhat.com> + */ + +asm( +".text\n" +".global _start\n" +"_start:\n" +" .short 0xaa55\n" +" .byte (_end - _start) / 512\n" +" lret\n" +" .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" +" .align 4, 0\n" +"_bev:\n" +".code16gcc\n" +/* DS = CS */ +" movw %cs, %ax\n" +" movw %ax, %ds\n" +" movl %esp, %ebp\n" +"run_linuxboot:\n" +" cli\n" +" cld\n" +" jmp load_kernel\n" +); + + +#include <stdint.h> +#include <byteswap.h> + +#define NO_QEMU_PROTOS +#include "../../include/hw/nvram/fw_cfg.h" + +#define BOOT_ROM_PRODUCT "Linux loader DMA" + +/* 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 _stringify(S) #S +#define stringify(S) _stringify(S) + +#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 uint16_t readw_addr32(const void *addr) { + uint16_t val; + asm("addr32 movw %1, %0" : "=r"(val) : "g"(addr)); + barrier(); + return val; +} + +static inline uint32_t readl_addr32(const void *addr) { + uint32_t val; + asm("addr32 movl %1, %0" : "=r"(val) : "g"(addr)); + barrier(); + return val; +} + +static inline void writel_addr32(void *addr, uint32_t val) { + barrier(); + asm("addr32 movl %0, %1" : : "r"(val), "g"(addr)); +} + +static inline uint64_t cpu_to_be64(uint64_t x) { + return bswap_64(x); +} + +static inline uint32_t cpu_to_be32(uint32_t x) { + return bswap_32(x); +} + +static inline uint32_t be32_to_cpu(uint32_t x) { + return bswap_32(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(); + } +} + +static uint32_t get_e801_addr(void) +{ + uint32_t eax, ebx, ecx, edx; + uint32_t ret; + + eax = 0xe801; + ebx = 0; + ecx = 0; + edx = 0; + asm("int $0x15\n" + : "+a"(eax) + : "b"(ebx), "c"(ecx), "d"(edx)); + + /* Output could be in AX/BX or CX/DX */ + if ((uint16_t)ecx || (uint16_t)edx) { + if(!(uint16_t)edx) { + /* Add 1 MB and convert to bytes */ + ret = (ecx + 1024) << 10; + } else { + /* Add 16 MB and convert to bytes */ + ret = (edx + 256) << 16; + } + } else { + if(!(uint16_t)ebx) { + /* Add 1 MB and convert to bytes */ + ret = (eax + 1024) << 10; + } else { + /* Add 16 MB and convert to bytes */ + ret = (ebx + 256) << 16; + } + } + + 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); + + if (readw_addr32(setup_addr + 0x206) < 0x203) { + /* Assume initrd_max 0x37ffffff */ + writel_addr32(setup_addr + 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_addr32(setup_addr + 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_addr32(setup_addr + 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)); +} + +asm( +"_manufacturer:\n" +".asciz \"QEMU\"\n" +"_product:\n" +".asciz "stringify(BOOT_ROM_PRODUCT)"\n" +".byte 0\n" +".align 512, 0\n" +"_end:\n" +); +
This optionrom is based on linuxboot.S. Signed-off-by: Marc Marí <markmb@redhat.com> --- .gitignore | 4 + hw/i386/pc.c | 9 +- hw/nvram/fw_cfg.c | 2 +- include/hw/nvram/fw_cfg.h | 1 + pc-bios/optionrom/Makefile | 6 +- pc-bios/optionrom/linuxboot_dma.c | 262 ++++++++++++++++++++++++++++++++++++++ 6 files changed, 280 insertions(+), 4 deletions(-) create mode 100644 pc-bios/optionrom/linuxboot_dma.c