[coreboot-gerrit] Change in ...coreboot[master]: mb/emulation/qemu-i440fx: add e820 interface

[Thomas Heijligen (Code Review)]

Thomas Heijligen has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/30848

Change subject: mb/emulation/qemu-i440fx: add e820 interface
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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 
---
M src/mainboard/emulation/qemu-i440fx/fw_cfg.c
M src/mainboard/emulation/qemu-i440fx/fw_cfg.h
2 files changed, 30 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/48/30848/1

diff --git a/src/mainboard/emulation/qemu-i440fx/fw_cfg.c b/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
index c5d6253..1890e66 100644
--- a/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
+++ b/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
@@ -83,6 +83,30 @@
    return fw_cfg_find_file(file, name);
 }

+static uint32_t fw_cfg_e820_size;
+static uint32_t fw_cfg_e820_pos;
+
+int fw_cfg_e820_select(void)
+{
+	FWCfgFile file;
+
+	if (!fw_cfg_present() || fw_cfg_find_file(&file, "etc/e820"))
+		return -1;
+	fw_cfg_select(file.select);
+	fw_cfg_e820_size = file.size;
+	return 0;
+}
+
+int fw_cfg_e820_read(FwCfgE820Entry *entry)
+{
+	if (fw_cfg_e820_pos + sizeof(*entry) > fw_cfg_e820_size)
+		return -1;
+
+	fw_cfg_read(entry, sizeof(*entry));
+	fw_cfg_e820_pos += sizeof(*entry);
+	return 0;
+}
+
 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 b5cdb92..eb07847 100644
--- a/src/mainboard/emulation/qemu-i440fx/fw_cfg.h
+++ b/src/mainboard/emulation/qemu-i440fx/fw_cfg.h
@@ -18,5 +18,11 @@
 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);
+/*
+ * Do not call any other fw_cfg_ function between fw_cfg_e820_select and
+ * fw_cfg_e820_read. This causes undefind behavior.
+ */
+int fw_cfg_e820_select(void);
+int fw_cfg_e820_read(FwCfgE820Entry *entry);

#endif /* FW_CFG_H */