Fix multiboot compilation
PATCH 1/1 Fix multiboot compilation
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.
Please also put this patch into -stable.
--- pc-bios/optionrom/linuxboot.S | 8 ++++---- pc-bios/optionrom/optionrom.h | 32 ++++++++++++++++++++++++-------- 2 files changed, 28 insertions(+), 12 deletions(-)
pc-bios/optionrom/linuxboot.S +4 -4
@@ -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
pc-bios/optionrom/optionrom.h +24 -8
@@ -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 \
Signature · 1 line
1.6.0.2
Aurelien Jarno
AppliedQuoted 15 lines · Alexander Graf
Commit
dd4239d6574ca41c94fc0d0f77ddc728510ffc57broke 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.
Quoted 7 lines
Please also put this patch into -stable.
Signed-off-by Alexander Graf <[email protected]>--- pc-bios/optionrom/linuxboot.S | 8 ++++---- pc-bios/optionrom/optionrom.h | 32 ++++++++++++++++++++++++-------- 2 files changed, 28 insertions(+), 12 deletions(-)
Thanks, applied.
Quoted 77 lines
pc-bios/optionrom/linuxboot.S +4
-4@@ -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, %eaxpc-bios/optionrom/optionrom.h +24
-8@@ -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 \Signature · 1 line
1.6.0.2
Signature · 2 lines
Aurelien Jarno GPG: 1024D/F1BCDB73 [email protected] http://www.aurel32.net