printf: Automatically prefix %p with 0x

According to the POSIX standard, %p is supposed to print a pointer "as
if by %#x", meaning the "0x" prefix should automatically be prepended.
All other implementations out there (glibc, Linux, even libpayload) do
this, so we should make coreboot match. This patch changes vtxprintf()
accordingly and removes any explicit instances of "0x%p" from existing
format strings.

How to handle zero padding is less clear: the official POSIX definition
above technically says there should be no automatic zero padding, but in
practice most other implementations seem to do it and I assume most
programmers would prefer it. The way chosen here is to always zero-pad
to 32 bits, even on a 64-bit system. The rationale for this is that even
on 64-bit systems, coreboot always avoids using any memory above 4GB for
itself, so in practice all pointers should fit in that range and padding
everything to 64 bits would just hurt readability. Padding it this way
also helps pointers that do exceed 4GB (e.g. prints from MMU config on
some arm64 systems) stand out better from the others.

Change-Id: I0171b52f7288abb40e3fc3c8b874aee14b9bdcd6
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37626
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: David Guckian

4 files changed, 6 insertions, 6 deletions

diff --git a/src/soc/intel/quark/bootblock/bootblock.c b/src/soc/intel/quark/bootblock/bootblock.c
index 2b2fc29f59..957b4a0c37 100644
--- a/src/soc/intel/quark/bootblock/bootblock.c
+++ b/src/soc/intel/quark/bootblock/bootblock.c
@@ -118,6 +118,6 @@ void bootblock_soc_init(void)
 void platform_prog_run(struct prog *prog)
 {
 	/* Display the program entry point */
-	printk(BIOS_SPEW, "Calling %s, 0x%p(0x%p)\n", prog->name,
+	printk(BIOS_SPEW, "Calling %s, %p(%p)\n", prog->name,
 		prog->entry, prog->arg);
 }
diff --git a/src/soc/intel/quark/i2c.c b/src/soc/intel/quark/i2c.c
index b09852bc3f..7ff2ddf93f 100644
--- a/src/soc/intel/quark/i2c.c
+++ b/src/soc/intel/quark/i2c.c
@@ -209,7 +209,7 @@ int platform_i2c_transfer(unsigned int bus, struct i2c_msg *segment,
 			if (index == 0)
 				printk(BIOS_ERR, "I2C Start\n");
 			printk(BIOS_ERR,
-				"I2C segment[%d]: %s 0x%02x %s 0x%p, 0x%08x bytes\n",
+				"I2C segment[%d]: %s 0x%02x %s %p, 0x%08x bytes\n",
 				index,
 				(segment[index].flags & I2C_M_RD) ? "Read from" : "Write to",
 				segment[index].slave,
diff --git a/src/soc/intel/quark/romstage/debug.c b/src/soc/intel/quark/romstage/debug.c
index 1029eadb93..e0cf6c8262 100644
--- a/src/soc/intel/quark/romstage/debug.c
+++ b/src/soc/intel/quark/romstage/debug.c
@@ -26,7 +26,7 @@ void soc_display_fspm_upd_params(const FSPM_UPD *fspm_old_upd,
 	new = &fspm_new_upd->FspmConfig;
 
 	/* Display the parameters for MemoryInit */
-	printk(BIOS_SPEW, "UPD values for MemoryInit at: 0x%p\n", new);
+	printk(BIOS_SPEW, "UPD values for MemoryInit at: %p\n", new);
 	fsp_display_upd_value("AddrMode", sizeof(old->AddrMode),
 		old->AddrMode, new->AddrMode);
 	fsp_display_upd_value("ChanMask", sizeof(old->ChanMask),
diff --git a/src/soc/intel/quark/romstage/fsp_params.c b/src/soc/intel/quark/romstage/fsp_params.c
index 681e126a13..c31cafb14f 100644
--- a/src/soc/intel/quark/romstage/fsp_params.c
+++ b/src/soc/intel/quark/romstage/fsp_params.c
@@ -111,13 +111,13 @@ void platform_fsp_memory_init_params_cb(FSPM_UPD *fspm_upd, uint32_t version)
 			"+-------------------+ 0x%08x (CONFIG_FSP_ESRAM_LOC)\n",
 			CONFIG_FSP_ESRAM_LOC);
 		printk(BIOS_SPEW, "| FSP stack         |\n");
-		printk(BIOS_SPEW, "+-------------------+ 0x%p\n",
+		printk(BIOS_SPEW, "+-------------------+ %p\n",
 			aupd->StackBase);
 		printk(BIOS_SPEW, "|                   |\n");
-		printk(BIOS_SPEW, "+-------------------+ 0x%p\n",
+		printk(BIOS_SPEW, "+-------------------+ %p\n",
 			_car_unallocated_start);
 		printk(BIOS_SPEW, "| coreboot data     |\n");
-		printk(BIOS_SPEW, "+-------------------+ 0x%p\n",
+		printk(BIOS_SPEW, "+-------------------+ %p\n",
 			_ecar_stack);
 		printk(BIOS_SPEW, "| coreboot stack    |\n");
 		printk(BIOS_SPEW,