summaryrefslogtreecommitdiff
path: root/hw/pc.c
diff options
context:
space:
mode:
Diffstat (limited to 'hw/pc.c')
-rw-r--r--hw/pc.c31
1 files changed, 18 insertions, 13 deletions
diff --git a/hw/pc.c b/hw/pc.c
index dc3193379..77bd05ec5 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -344,32 +344,37 @@ void pc_cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
/* various important CMOS locations needed by PC/Bochs bios */
/* memory size */
- val = 640; /* base memory in K */
+ /* base memory (first MiB) */
+ val = MIN(ram_size / 1024, 640);
rtc_set_memory(s, 0x15, val);
rtc_set_memory(s, 0x16, val >> 8);
-
- val = (ram_size / 1024) - 1024;
+ /* extended memory (next 64MiB) */
+ if (ram_size > 1024 * 1024) {
+ val = (ram_size - 1024 * 1024) / 1024;
+ } else {
+ val = 0;
+ }
if (val > 65535)
val = 65535;
rtc_set_memory(s, 0x17, val);
rtc_set_memory(s, 0x18, val >> 8);
rtc_set_memory(s, 0x30, val);
rtc_set_memory(s, 0x31, val >> 8);
-
- if (above_4g_mem_size) {
- rtc_set_memory(s, 0x5b, (unsigned int)above_4g_mem_size >> 16);
- rtc_set_memory(s, 0x5c, (unsigned int)above_4g_mem_size >> 24);
- rtc_set_memory(s, 0x5d, (uint64_t)above_4g_mem_size >> 32);
- }
-
- if (ram_size > (16 * 1024 * 1024))
- val = (ram_size / 65536) - ((16 * 1024 * 1024) / 65536);
- else
+ /* memory between 16MiB and 4GiB */
+ if (ram_size > 16 * 1024 * 1024) {
+ val = (ram_size - 16 * 1024 * 1024) / 65536;
+ } else {
val = 0;
+ }
if (val > 65535)
val = 65535;
rtc_set_memory(s, 0x34, val);
rtc_set_memory(s, 0x35, val >> 8);
+ /* memory above 4GiB */
+ val = above_4g_mem_size / 65536;
+ rtc_set_memory(s, 0x5b, val);
+ rtc_set_memory(s, 0x5c, val >> 8);
+ rtc_set_memory(s, 0x5d, val >> 16);
/* set the number of CPU */
rtc_set_memory(s, 0x5f, smp_cpus - 1);