From b65ec4efb64ddd9a06fa273237213d8b716b012e Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 11 Jul 2014 07:37:29 +0200 Subject: [PATCH 34/44] Fix multiboot compilation RH-Author: Paolo Bonzini Message-id: <1405064249-17652-1-git-send-email-pbonzini@redhat.com> Patchwork-id: 59770 O-Subject: [RHEL 6.6 qemu-kvm PATCH] Fix multiboot compilation Bugzilla: 820641 RH-Acked-by: Amos Kong RH-Acked-by: Igor Mammedov RH-Acked-by: Gerd Hoffmann From: Alexander Graf Bugzilla: 820641 Brew build: 7692734 Commit dd4239d6574ca41c94fc0d0f77ddc728510ffc57 broke multiboot. It replaced the instruction "rep insb (%dx), %es:(%edi)" by the binary output of "addr32 rep insb (%dx), %es:(%di)". Linuxboot calls the respective helper function in a code16 section. So the original instruction was automatically translated to its "addr32" equivalent. For multiboot, we're running in code32 so gcc didn't add the "addr32" which breaks the instruction. This patch splits that helper function in one which uses addr32 and one which does not, so everyone's happy. The good news is that nobody probably cared so far. The bundled multiboot.bin binary was built before the change and is thus correct. [Paolo: qemu-kvm's makefile rebuilds multiboot.bin, hence the bug] Please also put this patch into -stable. Signed-off-by: Alexander Graf Signed-off-by: Aurelien Jarno (cherry picked from commit 590bf491a49670843ee902c47f7ab1de5e9acd06) --- pc-bios/optionrom/linuxboot.S | 8 ++++---- pc-bios/optionrom/optionrom.h | 32 ++++++++++++++++++++++++-------- 2 files changed, 28 insertions(+), 12 deletions(-) Signed-off-by: Miroslav Rezanina --- pc-bios/optionrom/linuxboot.S | 8 ++++---- pc-bios/optionrom/optionrom.h | 32 ++++++++++++++++++++++++-------- 2 files changed, 28 insertions(+), 12 deletions(-) diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S index 8aebe51..c109363 100644 --- a/pc-bios/optionrom/linuxboot.S +++ b/pc-bios/optionrom/linuxboot.S @@ -106,10 +106,10 @@ copy_kernel: /* We're now running in 16-bit CS, but 32-bit ES! */ /* Load kernel and initrd */ - read_fw_blob(FW_CFG_KERNEL) - read_fw_blob(FW_CFG_INITRD) - read_fw_blob(FW_CFG_CMDLINE) - read_fw_blob(FW_CFG_SETUP) + read_fw_blob_addr32(FW_CFG_KERNEL) + read_fw_blob_addr32(FW_CFG_INITRD) + read_fw_blob_addr32(FW_CFG_CMDLINE) + read_fw_blob_addr32(FW_CFG_SETUP) /* And now jump into Linux! */ mov $0, %eax diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h index 4dcb906..fbdd48a 100644 --- a/pc-bios/optionrom/optionrom.h +++ b/pc-bios/optionrom/optionrom.h @@ -50,13 +50,7 @@ bswap %eax .endm -/* - * Read a blob from the fw_cfg device. - * Requires _ADDR, _SIZE and _DATA values for the parameter. - * - * Clobbers: %eax, %edx, %es, %ecx, %edi - */ -#define read_fw_blob(var) \ +#define read_fw_blob_pre(var) \ read_fw var ## _ADDR; \ mov %eax, %edi; \ read_fw var ## _SIZE; \ @@ -65,10 +59,32 @@ mov $BIOS_CFG_IOPORT_CFG, %edx; \ outw %ax, (%dx); \ mov $BIOS_CFG_IOPORT_DATA, %dx; \ - cld; \ + cld + +/* + * Read a blob from the fw_cfg device. + * Requires _ADDR, _SIZE and _DATA values for the parameter. + * + * Clobbers: %eax, %edx, %es, %ecx, %edi + */ +#define read_fw_blob(var) \ + read_fw_blob_pre(var); \ /* old as(1) doesn't like this insn so emit the bytes instead: \ rep insb (%dx), %es:(%edi); \ */ \ + .dc.b 0xf3,0x6c + +/* + * Read a blob from the fw_cfg device in forced addr32 mode. + * Requires _ADDR, _SIZE and _DATA values for the parameter. + * + * Clobbers: %eax, %edx, %es, %ecx, %edi + */ +#define read_fw_blob_addr32(var) \ + read_fw_blob_pre(var); \ + /* old as(1) doesn't like this insn so emit the bytes instead: \ + addr32 rep insb (%dx), %es:(%edi); \ + */ \ .dc.b 0x67,0xf3,0x6c #define OPTION_ROM_START \ -- 1.7.1