qemu: load e820 from fw_cfg
qemu 1.7+ provides a fw_cfg file named "etc/e820" with e820-like entries
for reservations and ram regions. Use it for ram detection if present,
otherwise fallback to the traditional cmos method.
Change-Id: Icac6c99d2a053e59dfdd28e48d1ceb3d56a61bdc
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-on: http://review.coreboot.org/4030
Tested-by: build bot (Jenkins)
diff --git a/src/mainboard/emulation/qemu-i440fx/northbridge.c b/src/mainboard/emulation/qemu-i440fx/northbridge.c
index c878689..0f8c0c2 100644
--- a/src/mainboard/emulation/qemu-i440fx/northbridge.c
+++ b/src/mainboard/emulation/qemu-i440fx/northbridge.c
@@ -13,6 +13,7 @@
#include <cbmem.h>
#include "fw_cfg.h"
+#include "fw_cfg_if.h"
#include "memory.c"
@@ -58,20 +59,62 @@
struct resource *res;
unsigned long tomk = 0, high;
int idx = 10;
+ int size;
pci_domain_read_resources(dev);
- tomk = qemu_get_memory_size();
- high = qemu_get_high_memory_size();
- printk(BIOS_DEBUG, "Detected %lu MiB RAM below 4G.\n", tomk / 1024);
- printk(BIOS_DEBUG, "Detected %lu MiB RAM above 4G.\n", high / 1024);
+ size = fw_cfg_check_file("etc/e820");
+ if (size > 0) {
+ /* supported by qemu 1.7+ */
+ FwCfgE820Entry *list = malloc(size);
+ int i;
+ fw_cfg_load_file("etc/e820", list);
+ for (i = 0; i < size/sizeof(*list); i++) {
+ switch (list[i].type) {
+ case 1: /* ram */
+ printk(BIOS_DEBUG, "QEMU: e820/ram: 0x%08llx +0x%08llx\n",
+ list[i].address, list[i].length);
+ if (list[i].address == 0) {
+ tomk = list[i].length / 1024;
+ ram_resource(dev, idx++, 0, 640);
+ ram_resource(dev, idx++, 768, tomk - 768);
+ } else {
+ ram_resource(dev, idx++,
+ list[i].address / 1024,
+ list[i].length / 1024);
+ }
+ break;
+ case 2: /* reserved */
+ printk(BIOS_DEBUG, "QEMU: e820/res: 0x%08llx +0x%08llx\n",
+ list[i].address, list[i].length);
+ res = new_resource(dev, idx++);
+ res->base = list[i].address;
+ res->size = list[i].length;
+ res->limit = 0xffffffff;
+ res->flags = IORESOURCE_MEM | IORESOURCE_FIXED |
+ IORESOURCE_STORED | IORESOURCE_ASSIGNED;
+ break;
+ default:
+ /* skip unknown */
+ break;
+ }
+ }
+ free(list);
+ }
- /* Report the memory regions. */
- idx = 10;
- ram_resource(dev, idx++, 0, 640);
- ram_resource(dev, idx++, 768, tomk - 768);
- if (high)
- ram_resource(dev, idx++, 4 * 1024 * 1024, high);
+ if (!tomk) {
+ /* qemu older than 1.7, or reading etc/e820 failed. Fallback to cmos. */
+ tomk = qemu_get_memory_size();
+ high = qemu_get_high_memory_size();
+ printk(BIOS_DEBUG, "QEMU: cmos: %lu MiB RAM below 4G.\n", tomk / 1024);
+ printk(BIOS_DEBUG, "QEMU: cmos: %lu MiB RAM above 4G.\n", high / 1024);
+
+ /* Report the memory regions. */
+ ram_resource(dev, idx++, 0, 640);
+ ram_resource(dev, idx++, 768, tomk - 768);
+ if (high)
+ ram_resource(dev, idx++, 4 * 1024 * 1024, high);
+ }
/* Reserve I/O ports used by QEMU */
qemu_reserve_ports(dev, idx++, 0x0510, 0x02, "firmware-config");