diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2014-10-06 16:49:57 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-10-09 15:36:15 +0200 |
| commit | cdebec5e40bd0af82da0659f37af85ee2aa2c9d1 (patch) | |
| tree | 7e355ce31516dbd959a49639e6f2ed15f6cb6e6f /pc-bios/optionrom/optionrom.h | |
| parent | fc02086b5ab8de50ce8234cf8f42b254de9e5d91 (diff) | |
linuxboot: compute initrd loading address
Even though hw/i386/pc.c tries to compute a valid loading address for the
initrd, close to the top of RAM, this does not take into account other
data that is malloced into that memory by SeaBIOS.
Luckily we can easily look at the memory map to find out how much memory is
used up there. This patch places the initrd in the first four gigabytes,
below the first hole (as returned by INT 15h, AX=e801h).
Without this patch:
[ 0.000000] init_memory_mapping: [mem 0x07000000-0x07fdffff]
[ 0.000000] RAMDISK: [mem 0x0710a000-0x07fd7fff]
With this patch:
[ 0.000000] init_memory_mapping: [mem 0x07000000-0x07fdffff]
[ 0.000000] RAMDISK: [mem 0x07112000-0x07fdffff]
So linuxboot is able to use the 64k that were added as padding for
QEMU <= 2.1.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'pc-bios/optionrom/optionrom.h')
| -rw-r--r-- | pc-bios/optionrom/optionrom.h | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h index ce436085d9..f1a9021ec1 100644 --- a/pc-bios/optionrom/optionrom.h +++ b/pc-bios/optionrom/optionrom.h @@ -51,8 +51,6 @@ .endm #define read_fw_blob_pre(var) \ - read_fw var ## _ADDR; \ - mov %eax, %edi; \ read_fw var ## _SIZE; \ mov %eax, %ecx; \ mov $var ## _DATA, %ax; \ @@ -68,6 +66,8 @@ * Clobbers: %eax, %edx, %es, %ecx, %edi */ #define read_fw_blob(var) \ + read_fw var ## _ADDR; \ + mov %eax, %edi; \ read_fw_blob_pre(var); \ /* old as(1) doesn't like this insn so emit the bytes instead: \ rep insb (%dx), %es:(%edi); \ @@ -80,7 +80,22 @@ * * Clobbers: %eax, %edx, %es, %ecx, %edi */ -#define read_fw_blob_addr32(var) \ +#define read_fw_blob_addr32(var) \ + read_fw var ## _ADDR; \ + mov %eax, %edi; \ + 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 + +/* + * Read a blob from the fw_cfg device in forced addr32 mode, address is in %edi. + * Requires _SIZE and _DATA values for the parameter. + * + * Clobbers: %eax, %edx, %edi, %es, %ecx + */ +#define read_fw_blob_addr32_edi(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); \ |