avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/arch/x86/lib/cmd_mtrr.c

@@ -0,0 +1,139 @@
+/*
+ * (C) Copyright 2014 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/msr.h>
+#include <asm/mtrr.h>
+
+static const char *const mtrr_type_name[MTRR_TYPE_COUNT] = {
+	"Uncacheable",
+	"Combine",
+	"2",
+	"3",
+	"Through",
+	"Protect",
+	"Back",
+};
+
+static int do_mtrr_list(void)
+{
+	int i;
+
+	printf("Reg Valid Write-type   %-16s %-16s %-16s\n", "Base   ||",
+	       "Mask   ||", "Size   ||");
+	for (i = 0; i < MTRR_COUNT; i++) {
+		const char *type = "Invalid";
+		uint64_t base, mask, size;
+		bool valid;
+
+		base = native_read_msr(MTRR_PHYS_BASE_MSR(i));
+		mask = native_read_msr(MTRR_PHYS_MASK_MSR(i));
+		size = ~mask & ((1ULL << CONFIG_CPU_ADDR_BITS) - 1);
+		size |= (1 << 12) - 1;
+		size += 1;
+		valid = mask & MTRR_PHYS_MASK_VALID;
+		type = mtrr_type_name[base & MTRR_BASE_TYPE_MASK];
+		printf("%d   %-5s %-12s %016llx %016llx %016llx\n", i,
+		       valid ? "Y" : "N", type, base & ~MTRR_BASE_TYPE_MASK,
+		       mask & ~MTRR_PHYS_MASK_VALID, size);
+	}
+
+	return 0;
+}
+
+static int do_mtrr_set(uint reg, int argc, char * const argv[])
+{
+	const char *typename = argv[0];
+	struct mtrr_state state;
+	uint32_t start, size;
+	uint64_t base, mask;
+	int i, type = -1;
+	bool valid;
+
+	if (argc < 3)
+		return CMD_RET_USAGE;
+	for (i = 0; i < MTRR_TYPE_COUNT; i++) {
+		if (*typename == *mtrr_type_name[i])
+			type = i;
+	}
+	if (type == -1) {
+		printf("Invalid type name %s\n", typename);
+		return CMD_RET_USAGE;
+	}
+	start = simple_strtoul(argv[1], NULL, 16);
+	size = simple_strtoul(argv[2], NULL, 16);
+
+	base = start | type;
+	valid = native_read_msr(MTRR_PHYS_MASK_MSR(reg)) & MTRR_PHYS_MASK_VALID;
+	mask = ~((uint64_t)size - 1);
+	mask &= (1ULL << CONFIG_CPU_ADDR_BITS) - 1;
+	if (valid)
+		mask |= MTRR_PHYS_MASK_VALID;
+
+	printf("base=%llx, mask=%llx\n", base, mask);
+	mtrr_open(&state);
+	wrmsrl(MTRR_PHYS_BASE_MSR(reg), base);
+	wrmsrl(MTRR_PHYS_MASK_MSR(reg), mask);
+	mtrr_close(&state);
+
+	return 0;
+}
+
+static int mtrr_set_valid(int reg, bool valid)
+{
+	struct mtrr_state state;
+	uint64_t mask;
+
+	mtrr_open(&state);
+	mask = native_read_msr(MTRR_PHYS_MASK_MSR(reg));
+	if (valid)
+		mask |= MTRR_PHYS_MASK_VALID;
+	else
+		mask &= ~MTRR_PHYS_MASK_VALID;
+	wrmsrl(MTRR_PHYS_MASK_MSR(reg), mask);
+	mtrr_close(&state);
+
+	return 0;
+}
+
+static int do_mtrr(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	const char *cmd;
+	uint reg;
+
+	cmd = argv[1];
+	if (argc < 2 || *cmd == 'l')
+		return do_mtrr_list();
+	argc -= 2;
+	argv += 2;
+	if (argc <= 0)
+		return CMD_RET_USAGE;
+	reg = simple_strtoul(argv[0], NULL, 16);
+	if (reg >= MTRR_COUNT) {
+		printf("Invalid register number\n");
+		return CMD_RET_USAGE;
+	}
+	if (*cmd == 'e')
+		return mtrr_set_valid(reg, true);
+	else if (*cmd == 'd')
+		return mtrr_set_valid(reg, false);
+	else if (*cmd == 's')
+		return do_mtrr_set(reg, argc - 1, argv + 1);
+	else
+		return CMD_RET_USAGE;
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	mtrr,	6,	1,	do_mtrr,
+	"Use x86 memory type range registers (32-bit only)",
+	"[list]        - list current registers\n"
+	"set <reg> <type> <start> <size>   - set a register\n"
+	"\t<type> is Uncacheable, Combine, Through, Protect, Back\n"
+	"disable <reg>      - disable a register\n"
+	"ensable <reg>      - enable a register"
+);