[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2] hvmloader: write extra memory in CMOS
There's a conventional protocol for virt BIOSes such as Boches, Seabios and OVMF to have the size of extra memory above 4GB be written to certain locations (0x5b-0x5d) in CMOS. So update these locations as well. Note that Seabios in Xen doesn't need this as it gets e820 directly from Xen. Rombios doesn't read this value. Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx> --- tools/firmware/hvmloader/hvmloader.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/tools/firmware/hvmloader/hvmloader.c b/tools/firmware/hvmloader/hvmloader.c index 1cc8cf2..9f692fb 100644 --- a/tools/firmware/hvmloader/hvmloader.c +++ b/tools/firmware/hvmloader/hvmloader.c @@ -146,6 +146,7 @@ static void init_hypercalls(void) static void cmos_write_memory_size(void) { uint32_t base_mem = 640, ext_mem, alt_mem; + uint64_t extra_mem = 0; alt_mem = ext_mem = hvm_info->low_mem_pgend << PAGE_SHIFT; ext_mem = (ext_mem > 0x0100000) ? (ext_mem - 0x0100000) >> 10 : 0; @@ -153,6 +154,15 @@ static void cmos_write_memory_size(void) ext_mem = 0xffff; alt_mem = (alt_mem > 0x1000000) ? (alt_mem - 0x1000000) >> 16 : 0; + /* According to hvm_info: + * 0x100000000 to page_to_phys(high_mem_pgend)-1: + * RAM above 4GB + * extra_mem written to CMOS is represented as 64kb chunks + */ + extra_mem = hvm_info->high_mem_pgend; + extra_mem = (extra_mem > 0x100000) ? + (((extra_mem - 0x100000) << PAGE_SHIFT) >> 16) : 0; + /* All BIOSes: conventional memory (CMOS *always* reports 640kB). */ cmos_outb(0x15, (uint8_t)(base_mem >> 0)); cmos_outb(0x16, (uint8_t)(base_mem >> 8)); @@ -166,6 +176,13 @@ static void cmos_write_memory_size(void) /* Some BIOSes: alternative extended memory (64kB chunks above 16MB). */ cmos_outb(0x34, (uint8_t)( alt_mem >> 0)); cmos_outb(0x35, (uint8_t)( alt_mem >> 8)); + + /* Used by virt BIOSes such as Boches, Seabios, OVMF etc: extra + * memory (64kB chunks above 4GB) + */ + cmos_outb(0x5d, (uint8_t)( extra_mem >> 16)); + cmos_outb(0x5c, (uint8_t)( extra_mem >> 8)); + cmos_outb(0x5b, (uint8_t)( extra_mem >> 0)); } /* -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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