Change in coreboot[master]: soc/cavium/bootblock: Get rid of register X1

[Patrick Rudolph (Code Review)]

Patrick Rudolph has uploaded this change for review. ( https://review.coreboot.org/23792

Change subject: soc/cavium/bootblock: Get rid of register X1
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soc/cavium/bootblock: Get rid of register X1

The register X1 isn't used. Document it and remove it.

Change-Id: I9324ea9de24ba4baaef9dde890c443dd0f921ad9
Signed-off-by: Patrick Rudolph 
---
M src/soc/cavium/cn81xx/bootblock_custom.S
M src/soc/cavium/common/bootblock.c
M src/soc/cavium/common/include/soc/bootblock.h
3 files changed, 7 insertions(+), 8 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/92/23792/1

diff --git a/src/soc/cavium/cn81xx/bootblock_custom.S b/src/soc/cavium/cn81xx/bootblock_custom.S
index 69985b7..2f503c8 100644
--- a/src/soc/cavium/cn81xx/bootblock_custom.S
+++ b/src/soc/cavium/cn81xx/bootblock_custom.S
@@ -29,7 +29,11 @@
      */
     ic      ialluis
     fmov    d30, x0     /* Save X0 in FPR for use later */
-    fmov    d31, x1     /* Save X1 in FPR for use later */
+     /**
+      * The BDK stores X1 for later use, but it turns out that we don't need
+      * this "feature". The idea is to hide the devicetree somewhere in
+      * flash, that only the ROM will find it and point to it using X1.
+      */
     adr     x1, _start  /* x1 = _start location based on PC */
     fmov    d29, x1     /* Save PC in FPR for use later */

@@ -84,7 +88,7 @@
     adr     x0, _start

/**
-     * Check if IROM has loaded the code to CONFIG_BOOTROM_OFFSET.
+     * Check if IROM has loaded the code to BOOTROM_OFFSET.
      * In case the offset is wrong, try to relocate.
      * Ideally the following code is never executed.
      * FIXME: Add region overlap check.
@@ -248,8 +252,7 @@
     bl      arm64_init_cpu

fmov    x0, d30 /* The original X0, info from previous image */
-    fmov    x1, d31 /* The original X1, info from previous image */
-    fmov    x2, d29 /* The original PC we were loaded at */
+    fmov    x1, d29 /* The original PC we were loaded at */

/* Call C entry */
     bl      bootblock_main
diff --git a/src/soc/cavium/common/bootblock.c b/src/soc/cavium/common/bootblock.c
index c61a8d7..7b9d524 100644
--- a/src/soc/cavium/common/bootblock.c
+++ b/src/soc/cavium/common/bootblock.c
@@ -32,7 +32,6 @@

/* C code entry point for the boot block */
 void bootblock_main(const uint64_t reg_x0,
-		    const uint64_t reg_x1,
    	    const uint64_t reg_pc)
 {
    uint64_t base_timestamp = 0;
@@ -57,8 +56,6 @@
    		printk(BIOS_ERR,
    		       "BOOTBLOCK: RST Boot Failure Code %lld\n",
    		       reg_x0);
-
-		printk(BIOS_DEBUG, "BOOTBLOCK: FDT 0x%llX\n", reg_x1);
    }

bootblock_soc_init();
diff --git a/src/soc/cavium/common/include/soc/bootblock.h b/src/soc/cavium/common/include/soc/bootblock.h
index e347e86..bfb9745 100644
--- a/src/soc/cavium/common/include/soc/bootblock.h
+++ b/src/soc/cavium/common/include/soc/bootblock.h
@@ -14,7 +14,6 @@
 void bootblock_mainboard_init(void);

void bootblock_main(const uint64_t reg_x0,
-		    const uint64_t reg_x1,
    	    const uint64_t reg_pc);