rampayload: Add the linuxcheck payload

The i386.c file uses standard 3f8 UART for some simple diagnostic
prints, and the libpayload console otherwise.

This payload was used to debug Linux as a rampayload and was very helpful
for that work.

Change-Id: I1cce5528780cd825fd91a88137fa70abd9f218e7
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/28600
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

payloads/linuxcheck/Makefile

@@ -0,0 +1,37 @@
+LIBPAYLOAD_DIR=$(CURDIR)/libpayload
+XCOMPILE=$(LIBPAYLOAD_DIR)/libpayload.xcompile
+# build libpayload and put .config file in $(CURDIR) instead of ../libpayload
+# to avoid pollute the libpayload source directory and possible conflicts
+LPOPTS=obj="$(CURDIR)/build" DESTDIR="$(CURDIR)" DOTCONFIG="$(CURDIR)/.config"
+CFLAGS += -Wall -Werror -Os -ffreestanding -nostdinc -nostdlib
+ifeq ($(CONFIG_ARCH_X86),y)
+TARGETARCH = i386
+endif
+
+all: linuxcheck.elf
+
+$(LIBPAYLOAD_DIR):
+	$(MAKE) -C ../libpayload $(LPOPTS) defconfig
+	$(MAKE) -C ../libpayload $(LPOPTS)
+	$(MAKE) -C ../libpayload $(LPOPTS) install
+
+ifneq ($(strip $(wildcard libpayload)),)
+include $(XCOMPILE)
+LPGCC = CC="$(GCC_CC_x86_32)" "$(LIBPAYLOAD_DIR)/bin/lpgcc"
+%.elf: %.c Makefile
+	$(LPGCC) $(CFLAGS) -o $*.elf $*.c $(TARGETARCH).c
+else
+# If libpayload is not found, first build libpayload,
+# then do the make, this time it'll find libpayload
+# and generate the linuxcheck.elf target
+%.elf: $(LIBPAYLOAD_DIR)
+	$(MAKE) all
+endif
+
+clean:
+	rm -f linuxcheck.elf
+
+distclean: clean
+	rm -rf build libpayload .config .config.old
+
+.PHONY: all clean distclean

payloads/linuxcheck/i386.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the coreinfo project.
+ *
+ * Copyright (C) 2018 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <libpayload-config.h>
+#include <libpayload.h>
+#include "linuxcheck.h"
+
+void buts(char *s)
+{
+	int i;
+	for (i = 0; i < strlen(s); i++)
+		outb(s[i], 0x3f8);
+}
+
+void hex4(u8 c)
+{
+	static char *hex = "0123456789abcdef";
+	outb(hex[c & 0xf], 0x3f8);
+}
+
+void hex8(u8 c)
+{
+	hex4(c >> 4);
+	hex4(c);
+}
+
+void hex16(u16 c)
+{
+	hex8((u8)(c >> 8));
+	hex8((u8)c);
+}
+void hex32(u32 c)
+{
+	hex16((u16)(c >> 16));
+	hex16((u16)c);
+}

payloads/linuxcheck/linuxcheck.c

@@ -0,0 +1,52 @@
+/*
+ * This file is part of the coreinfo project.
+ *
+ * Copyright (C) 2018 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <libpayload-config.h>
+#include <libpayload.h>
+#include "linuxcheck.h"
+
+extern struct console_output_driver *console_out;
+extern struct sysinfo_t lib_sysinfo;
+
+int main(void)
+{
+	int ret, i;
+
+	buts("Greetings from linuxcheck, via hard-coded calls to serial functions.\n");
+	if (console_out == NULL)
+		buts("Bad news: console_out is NULL\n");
+	if (lib_sysinfo.serial == NULL)
+		buts("Bad news: lib_sysinfo.serial is NULL. Very little will work well.\n");
+	ret = lib_get_sysinfo();
+	if (ret) {
+		buts("lib_get_sysinfo() is non-zero");
+		hex32(ret);
+		buts("\n");
+	}
+
+	buts("The next line should be puts works\n");
+	puts("puts works\n");
+	buts("If you did not see puts works, then you have a console issues\n");
+	buts("The next line should be 'printf works'\n");
+	printf("printf works\n");
+	buts(" ... if you did not see printf works, then you have a printf issue\n");
+	printf("Number of memory ranges: %d\n", lib_sysinfo.n_memranges);
+	for (i = 0; i < lib_sysinfo.n_memranges; i++) {
+		printf("%d: base 0x%08llx size 0x%08llx type 0x%x\n", i, lib_sysinfo.memrange[i].base, lib_sysinfo.memrange[i].size, lib_sysinfo.memrange[i].type);
+	}
+	buts("Now we will halt. Bye");
+	halt();
+	return 0;
+}

payloads/linuxcheck/linuxcheck.h

@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2018 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/* buts is a programmed IO byte puts, which you need to write for all platforms. */
+void buts(char *s);
+
+void hex4(u8 c);
+void hex8(u8 c);
+void hex16(u16 c);
+void hex32(u32 c);