mb/emulation/qemu-i440fx: prepare fw_cfg for romstage usage

Add separate functions for selecting the port and reading the port.
Romstage can now read incremental from the data port.

Change-Id: I0ffde3bc2a4415a8af99af2275d16f6609099e37
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Reviewed-on: https://review.coreboot.org/c/30846
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/src/mainboard/emulation/qemu-i440fx/fw_cfg.c b/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
index 9b394f2e00..364221eacc 100644
--- a/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
+++ b/src/mainboard/emulation/qemu-i440fx/fw_cfg.c
@@ -42,12 +42,22 @@ static int fw_cfg_present(void)
 	return fw_cfg_detected;
 }
 
-void fw_cfg_get(int entry, void *dst, int dstlen)
+static void fw_cfg_select(uint16_t entry)
 {
 	outw(entry, FW_CFG_PORT_CTL);
+}
+
+static void fw_cfg_read(void *dst, int dstlen)
+{
 	insb(FW_CFG_PORT_DATA, dst, dstlen);
 }
 
+void fw_cfg_get(uint16_t entry, void *dst, int dstlen)
+{
+	fw_cfg_select(entry);
+	fw_cfg_read(dst, dstlen);
+}
+
 static void fw_cfg_init_file(void)
 {
 	u32 i, size, count = 0;