mpc85xx: add SPI kernel loader for TP-Link TL-WDR4900 v1

Similar to the lzma-loader on our MIPS targets, the spi-loader acts as
a second-stage loader that will then load and start the actual kernel.
As the TL-WDR4900 uses SPI-NOR and the P1010 family does not have support
for memory mapping of this type of flash, this loader needs to contain a
basic driver for the FSL ESPI controller.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

1 files changed, 59 insertions, 0 deletions

diff --git a/target/linux/mpc85xx/image/spi-loader/stdio.c b/target/linux/mpc85xx/image/spi-loader/stdio.c
new file mode 100644
index 0000000000..3aa55d0613
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/stdio.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#include <stdio.h>
+
+int puts(const char *s)
+{
+	while (*s)
+		putchar(*s++);
+	return 0;
+}
+
+void put_u4(uint8_t v)
+{
+	v &= 0xf;
+	switch (v) {
+	case 0x0 ... 0x9:
+		putchar('0' + v);
+		break;
+	case 0xa ... 0xf:
+		putchar('a' + (v - 0xa));
+	}
+}
+
+void put_u8(uint8_t v)
+{
+	put_u4(v >> 4);
+	put_u4(v);
+}
+
+void put_u16(uint16_t v)
+{
+	put_u8(v >> 8);
+	put_u8(v);
+}
+
+void put_u32(uint32_t v)
+{
+	put_u16(v >> 16);
+	put_u16(v);
+}
+
+void put_ptr(const void *p)
+{
+	put_u32((uint32_t)p);
+}
+
+void put_array(const void *p, size_t l)
+{
+	const uint8_t *c = p;
+	size_t i;
+	for (i = 0; i < l; i++) {
+		put_u8(c[i]);
+		putchar(' ');
+	}
+	putchar('\n');
+}