mb/emulation/qemu-i440fx: add e820 interface
Qemu provides e820 table at fw_cfg interface. Add functions to access it.
Change-Id: I547bc7fef09999baa28149a6325cbca91e31e99b
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Reviewed-on: https://review.coreboot.org/c/30848
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/src/mainboard/emulation/qemu-i440fx/fw_cfg.c b/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
index b859bdb..c5d5a47 100644
--- a/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
+++ b/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
@@ -83,6 +83,45 @@
return fw_cfg_find_file(file, name);
}
+static int fw_cfg_e820_select(uint32_t *size)
+{
+ FWCfgFile file;
+
+ if (!fw_cfg_present() || fw_cfg_find_file(&file, "etc/e820"))
+ return -1;
+ fw_cfg_select(file.select);
+ *size = file.size;
+ return 0;
+}
+
+static int fw_cfg_e820_read(FwCfgE820Entry *entry, uint32_t *size,
+ uint32_t *pos)
+{
+ if (*pos + sizeof(*entry) > *size)
+ return -1;
+
+ fw_cfg_read(entry, sizeof(*entry));
+ *pos += sizeof(*entry);
+ return 0;
+}
+
+/* returns tolud on success or 0 on failure */
+uintptr_t fw_cfg_tolud(void)
+{
+ FwCfgE820Entry e;
+ uint64_t top = 0;
+ uint32_t size = 0, pos = 0;
+
+ if (fw_cfg_e820_select(&size)) {
+ while (!fw_cfg_e820_read(&e, &size, &pos)) {
+ uint64_t limit = e.address + e.length;
+ if (e.type == 1 && limit < 4ULL * GiB && limit > top)
+ top = limit;
+ }
+ }
+ return (uintptr_t)top;
+}
+
int fw_cfg_max_cpus(void)
{
unsigned short max_cpus;
diff --git a/src/mainboard/emulation/qemu-i440fx/fw_cfg.h b/src/mainboard/emulation/qemu-i440fx/fw_cfg.h
index 91b758c..975801b 100644
--- a/src/mainboard/emulation/qemu-i440fx/fw_cfg.h
+++ b/src/mainboard/emulation/qemu-i440fx/fw_cfg.h
@@ -18,5 +18,6 @@
int fw_cfg_check_file(FWCfgFile *file, const char *name);
int fw_cfg_max_cpus(void);
unsigned long fw_cfg_smbios_tables(int *handle, unsigned long *current);
+uintptr_t fw_cfg_tolud(void);
#endif /* FW_CFG_H */