--- /dev/null
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (C) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+
+CONFIG ?= $(error No configuration set)
+
+include config/$(CONFIG).mk
+
+MKIMAGE := mkimage
+KARCH := powerpc
+CC := $(CROSS_COMPILE)gcc
+LD := $(CROSS_COMPILE)ld
+OBJCOPY := $(CROSS_COMPILE)objcopy
+
+PROGRAM_NAME := MPC85xx SPI loader
+
+BIN_FLAGS := -O binary --pad-to=$(PAD_TO)
+
+CFLAGS += -std=gnu17 -Os -Wall -Wstrict-prototypes \
+ -fomit-frame-pointer -ffreestanding \
+ -ffunction-sections -fno-pic \
+ -Iinclude -include ../config/$(CONFIG).h \
+ -DCONFIG_PROGRAM_NAME='"$(PROGRAM_NAME)"' \
+ -DCONFIG_IMAGE_OFFSET=$(IMAGE_OFFSET)
+ASFLAGS := $(CFLAGS)
+
+LDS := loader.lds
+LDFLAGS := -static --gc-sections -T $(LDS) -Ttext $(TEXT_START)
+
+OBJECTS := head.o loader.o string.o stdio.o drivers/serial/ns16550.o \
+ drivers/spi/fsl_espi.o drivers/spi/spi-nor.o
+
+OUTDIR := out
+
+all: $(OUTDIR)/uImage
+
+-include $(OBJECTS:%.o=$(OUTDIR)/%.d)
+
+$(OUTDIR)/%.o: %.c Makefile config/$(CONFIG).mk
+ @mkdir -p $(dir $@)
+ $(CC) $(CFLAGS) -c -o $@ -MD -MP $<
+
+$(OUTDIR)/%.o: %.S Makefile config/$(CONFIG).mk
+ @mkdir -p $(dir $@)
+ $(CC) $(ASFLAGS) -c -o $@ -MD -MP $<
+
+$(OUTDIR)/loader.elf: $(OBJECTS:%=$(OUTDIR)/%) $(LDS)
+ $(LD) $(LDFLAGS) -o $@ $(OBJECTS:%=$(OUTDIR)/%)
+
+$(OUTDIR)/loader.bin: $(OUTDIR)/loader.elf
+ $(OBJCOPY) $(BIN_FLAGS) $< $@
+
+$(OUTDIR)/uImage: $(OUTDIR)/loader.bin
+ $(MKIMAGE) -A $(KARCH) -O linux -T kernel -C none \
+ -a $(TEXT_START) -e $(TEXT_START) -n '$(PROGRAM_NAME)' -d $< $@
+
+clean:
+ rm -rf $(OUTDIR)
+
+.PHONY: all clean
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#define CONFIG_FREQ_SYSTEMBUS 399999996
+#define CONFIG_SPI_MAX_HZ 25000000
+
+#define CONFIG_SERIAL_NS16550_REG_BASE 0xffe04500
+#define CONFIG_SERIAL_NS16550_REG_SHIFT 0
+
+#define CONFIG_SPI_FSL_ESPI_REG_BASE 0xffe07000
--- /dev/null
+TEXT_START := 0x800000
+
+# It seems that the TP-Link TL-WDR4900 U-Boot does not flush the cache before
+# jumping into the uImage. Padding the image to 32k seems make the boot work
+# reliably.
+#
+# We leave 0x40 for the uImage header, which allows us to append the kernel
+# uImage after the loader and read with an added offset 0x8000 from the
+# SPI flash.
+PAD_TO := 0x807fc0
+
+# Kernel begins at 0x60200 in flash, loader adds 0x8000
+IMAGE_OFFSET := 0x68200
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 16550 serial console support.
+ *
+ * Original copied from <file:arch/ppc/boot/common/ns16550.c>
+ * (which had no copyright)
+ * Modifications: 2006 (c) MontaVista Software, Inc.
+ *
+ * Modified by: Mark A. Greer <mgreer@mvista.com>
+ *
+ * Adapted by:
+ *
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#include <io.h>
+#include <serial.h>
+
+#define UART_DLL 0 /* Out: Divisor Latch Low */
+#define UART_DLM 1 /* Out: Divisor Latch High */
+#define UART_FCR 2 /* Out: FIFO Control Register */
+#define UART_LCR 3 /* Out: Line Control Register */
+#define UART_MCR 4 /* Out: Modem Control Register */
+#define UART_LSR 5 /* In: Line Status Register */
+#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
+#define UART_LSR_DR 0x01 /* Receiver data ready */
+#define UART_MSR 6 /* In: Modem Status Register */
+#define UART_SCR 7 /* I/O: Scratch Register */
+
+static uint8_t *const reg_base = (uint8_t *)CONFIG_SERIAL_NS16550_REG_BASE;
+static const int reg_shift = CONFIG_SERIAL_NS16550_REG_SHIFT;
+
+void serial_console_putchar(char c)
+{
+ while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_THRE) == 0);
+ out_8(reg_base, c);
+}
+
+int serial_console_getc(void)
+{
+ while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) == 0);
+ return in_8(reg_base);
+}
+
+int serial_console_tstc(void)
+{
+ return ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) != 0);
+}
+
+void serial_console_init(void)
+{
+ out_8(reg_base + (UART_FCR << reg_shift), 0x06);
+}
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * eSPI controller driver.
+ *
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ *
+ * Based on U-Boot code:
+ *
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
+ * Copyright 2020 NXP
+ * Author: Mingkai Hu (Mingkai.hu@freescale.com)
+ * Chuanhua Han (chuanhua.han@nxp.com)
+ */
+
+#include <io.h>
+#include <stdio.h>
+#include <spi.h>
+
+/* eSPI Registers */
+typedef struct ccsr_espi {
+ uint32_t mode; /* eSPI mode */
+ uint32_t event; /* eSPI event */
+ uint32_t mask; /* eSPI mask */
+ uint32_t com; /* eSPI command */
+ uint32_t tx; /* eSPI transmit FIFO access */
+ uint32_t rx; /* eSPI receive FIFO access */
+ uint8_t res1[8]; /* reserved */
+ uint32_t csmode[4]; /* 0x2c: sSPI CS0/1/2/3 mode */
+ uint8_t res2[4048]; /* fill up to 0x1000 */
+} ccsr_espi_t;
+
+struct fsl_spi {
+ ccsr_espi_t *espi;
+ uint32_t cs;
+ uint32_t div16;
+ uint32_t pm;
+ uint32_t mode;
+};
+
+#define ESPI_MAX_CS_NUM 4
+#define ESPI_FIFO_WIDTH_BIT 32
+
+#define ESPI_EV_RNE BIT(9)
+#define ESPI_EV_TNF BIT(8)
+#define ESPI_EV_DON BIT(14)
+#define ESPI_EV_TXE BIT(15)
+#define ESPI_EV_RFCNT_SHIFT 24
+#define ESPI_EV_RFCNT_MASK (0x3f << ESPI_EV_RFCNT_SHIFT)
+
+#define ESPI_MODE_EN BIT(31) /* Enable interface */
+#define ESPI_MODE_TXTHR(x) ((x) << 8) /* Tx FIFO threshold */
+#define ESPI_MODE_RXTHR(x) ((x) << 0) /* Rx FIFO threshold */
+
+#define ESPI_COM_CS(x) ((x) << 30)
+#define ESPI_COM_TRANLEN(x) ((x) << 0)
+
+#define ESPI_CSMODE_CI_INACTIVEHIGH BIT(31)
+#define ESPI_CSMODE_CP_BEGIN_EDGCLK BIT(30)
+#define ESPI_CSMODE_REV_MSB_FIRST BIT(29)
+#define ESPI_CSMODE_DIV16 BIT(28)
+#define ESPI_CSMODE_PM(x) ((x) << 24)
+#define ESPI_CSMODE_POL_ASSERTED_LOW BIT(20)
+#define ESPI_CSMODE_LEN(x) ((x) << 16)
+#define ESPI_CSMODE_CSBEF(x) ((x) << 12)
+#define ESPI_CSMODE_CSAFT(x) ((x) << 8)
+#define ESPI_CSMODE_CSCG(x) ((x) << 3)
+
+#define ESPI_CSMODE_INIT_VAL (ESPI_CSMODE_POL_ASSERTED_LOW | \
+ ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
+ ESPI_CSMODE_CSCG(1))
+
+#define ESPI_MAX_DATA_TRANSFER_LEN 0x10000
+
+static int espi_xfer(struct fsl_spi *fsl, const struct spi_transfer *msg, int n)
+{
+ ccsr_espi_t *espi = fsl->espi;
+ size_t len = spi_message_len(msg, n);
+
+ if (len > ESPI_MAX_DATA_TRANSFER_LEN)
+ return -1;
+
+ /* clear the RXCNT and TXCNT */
+ out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
+ out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);
+ out_be32(&espi->com, ESPI_COM_CS(fsl->cs) | ESPI_COM_TRANLEN(len - 1));
+
+ int last_msg = n - 1;
+ int tx_msg = -1, rx_msg = -1;
+ size_t tx_len = 0, rx_len = 0, tx_pos = 0, rx_pos = 0;
+
+ while (true) {
+ if (tx_pos == tx_len && tx_msg < last_msg) {
+ tx_msg++;
+ tx_pos = 0;
+ tx_len = msg[tx_msg].len;
+ }
+ if (rx_pos == rx_len && rx_msg < last_msg) {
+ rx_msg++;
+ rx_pos = 0;
+ rx_len = msg[rx_msg].len;
+ }
+ if (rx_pos == rx_len)
+ break;
+
+ const uint8_t *tx_buf = msg[tx_msg].tx_buf;
+ uint8_t *rx_buf = msg[rx_msg].rx_buf;
+
+ uint32_t event = in_be32(&espi->event);
+
+ /* TX */
+ if ((event & ESPI_EV_TNF) && tx_len > 0) {
+ uint8_t v = 0;
+ if (tx_buf)
+ v = tx_buf[tx_pos];
+ out_8((uint8_t *)&espi->tx, v);
+ tx_pos++;
+ }
+
+ /* RX */
+ if (event & ESPI_EV_RNE) {
+ uint8_t v = in_8((uint8_t *)&espi->rx);
+ if (rx_buf)
+ rx_buf[rx_pos] = v;
+ rx_pos++;
+ }
+ }
+
+ return 0;
+}
+
+static void espi_claim_bus(struct fsl_spi *fsl)
+{
+ ccsr_espi_t *espi = fsl->espi;
+ uint32_t csmode;
+ int i;
+
+ /* Enable eSPI interface */
+ out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
+ | ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
+
+ out_be32(&espi->mask, 0x00000000); /* Mask all eSPI interrupts */
+
+ /* Init CS mode interface */
+ for (i = 0; i < ESPI_MAX_CS_NUM; i++)
+ out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
+
+ csmode = ESPI_CSMODE_INIT_VAL;
+
+ /* Set eSPI BRG clock source */
+ csmode |= ESPI_CSMODE_PM(fsl->pm) | fsl->div16;
+
+ /* Set eSPI mode */
+ if (fsl->mode & SPI_CPHA)
+ csmode |= ESPI_CSMODE_CP_BEGIN_EDGCLK;
+ if (fsl->mode & SPI_CPOL)
+ csmode |= ESPI_CSMODE_CI_INACTIVEHIGH;
+
+ /* Character bit order: msb first */
+ csmode |= ESPI_CSMODE_REV_MSB_FIRST;
+
+ /* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
+ csmode |= ESPI_CSMODE_LEN(7);
+
+ out_be32(&espi->csmode[fsl->cs], csmode);
+}
+
+static void espi_release_bus(struct fsl_spi *fsl)
+{
+ /* Disable the SPI hardware */
+ out_be32(&fsl->espi->mode,
+ in_be32(&fsl->espi->mode) & (~ESPI_MODE_EN));
+}
+
+static void espi_setup_spi(struct fsl_spi *fsl, unsigned int max_hz)
+{
+ unsigned long spibrg;
+ uint32_t pm;
+
+ spibrg = CONFIG_FREQ_SYSTEMBUS / 2;
+ fsl->div16 = 0;
+ if ((spibrg / max_hz) > 32) {
+ fsl->div16 = ESPI_CSMODE_DIV16;
+ pm = spibrg / (max_hz * 16 * 2);
+ if (pm > 16) {
+ /* max_hz too low */
+ pm = 16;
+ }
+ } else {
+ pm = spibrg / (max_hz * 2);
+ }
+ if (pm)
+ pm--;
+ fsl->pm = pm;
+}
+
+static struct fsl_spi spi;
+
+int spi_init(unsigned int cs, unsigned int max_hz, unsigned int mode)
+{
+ if (cs >= ESPI_MAX_CS_NUM)
+ return -1;
+
+ spi.espi = (ccsr_espi_t *)CONFIG_SPI_FSL_ESPI_REG_BASE;
+ spi.cs = cs;
+ spi.mode = mode;
+
+ espi_setup_spi(&spi, max_hz);
+
+ return 0;
+}
+
+int spi_claim_bus(void)
+{
+ espi_claim_bus(&spi);
+
+ return 0;
+}
+
+void spi_release_bus(void)
+{
+ espi_release_bus(&spi);
+}
+
+int spi_xfer(const struct spi_transfer *msg, int n)
+{
+ return espi_xfer(&spi, msg, n);
+}
+
+size_t spi_max_xfer(void)
+{
+ return ESPI_MAX_DATA_TRANSFER_LEN;
+}
--- /dev/null
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#include <spi.h>
+#include <spi-nor.h>
+#include <stdio.h>
+
+#define CMD_READ 0x03
+#define CMD_READ_ID 0x9F
+
+int spi_nor_read_id(void)
+{
+ int ret;
+
+ const uint8_t tx_buf[1] = {CMD_READ_ID};
+ uint8_t rx_buf[3] = {};
+ struct spi_transfer t[2] = {{
+ .tx_buf = tx_buf,
+ .rx_buf = NULL,
+ .len = sizeof(tx_buf),
+ }, {
+ .tx_buf = NULL,
+ .rx_buf = rx_buf,
+ .len = sizeof(rx_buf),
+ }};
+
+ ret = spi_xfer(t, ARRAY_SIZE(t));
+ if (ret) {
+ puts("SPI transfer failed\n");
+ return ret;
+ }
+
+ puts("Flash JECED ID: ");
+ put_array(rx_buf, sizeof(rx_buf));
+
+ return 0;
+}
+
+int spi_nor_read_data(void *dest, size_t pos, size_t len)
+{
+ int ret;
+
+ while (len > 0) {
+ uint8_t cmd[4] = {CMD_READ, pos >> 16, pos >> 8, pos};
+ size_t block_len = min(len, spi_max_xfer() - sizeof(cmd));
+
+ struct spi_transfer t[2] = {{
+ .tx_buf = cmd,
+ .rx_buf = NULL,
+ .len = sizeof(cmd),
+ }, {
+ .tx_buf = NULL,
+ .rx_buf = dest,
+ .len = block_len,
+ }};
+
+ ret = spi_xfer(t, ARRAY_SIZE(t));
+ if (ret) {
+ puts("SPI transfer failed\n");
+ return ret;
+ }
+
+ pos += block_len;
+ dest += block_len;
+ len -= block_len;
+ }
+
+ return 0;
+}
+
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ *
+ * Based on Linux arch/powerpc/boot/crt0.S, which is:
+ *
+ * Copyright (C) Paul Mackerras 1997.
+ */
+
+#include <ppc_asm.h>
+
+ .text
+ .global _start
+_start:
+ /* Do a cache flush for our text, in case the loader didn't */
+ lis r3,_text_start@ha
+ addi r3,r3,_text_start@l
+ li r4,_text_len
+ bl flush_cache
+
+ /* Clear the BSS */
+ lis r3,_bss_start@ha
+ addi r3,r3,_bss_start@l
+ li r4,0
+ li r5,_bss_len
+ bl memset
+
+ /* Set up stack */
+ lis r1,_stack_top@ha
+ addi r1,r1,_stack_top@l
+ /* Establish a stack frame */
+ li r0,0
+ stwu r0,-16(r1)
+
+ /* Call start */
+ b start
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Derived from U-Boot include/image.h:
+ *
+ * (C) Copyright 2008 Semihalf
+ *
+ * (C) Copyright 2000-2005
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ ********************************************************************
+ * NOTE: This header file defines an interface to U-Boot. Including
+ * this (unmodified) header file in another file is considered normal
+ * use of U-Boot, and does *not* fall under the heading of "derived
+ * work".
+ ********************************************************************
+ */
+
+#pragma once
+
+#include <types.h>
+
+/*
+ * Compression Types
+ *
+ * The following are exposed to uImage header.
+ * New IDs *MUST* be appended at the end of the list and *NEVER*
+ * inserted for backward compatibility.
+ */
+enum {
+ IH_COMP_NONE = 0, /* No Compression Used */
+ IH_COMP_GZIP, /* gzip Compression Used */
+ IH_COMP_BZIP2, /* bzip2 Compression Used */
+ IH_COMP_LZMA, /* lzma Compression Used */
+ IH_COMP_LZO, /* lzo Compression Used */
+ IH_COMP_LZ4, /* lz4 Compression Used */
+ IH_COMP_ZSTD, /* zstd Compression Used */
+
+ IH_COMP_COUNT,
+};
+
+#define IH_MAGIC 0x27051956 /* Image Magic Number */
+#define IH_MAGIC_OKLI 0x4f4b4c49 /* 'OKLI' Magic Number */
+#define IH_NMLEN 32 /* Image Name Length */
+
+/*
+ * Legacy format image header,
+ * all data in network byte order (aka natural aka bigendian).
+ */
+typedef struct image_header {
+ uint32_t ih_magic; /* Image Header Magic Number */
+ uint32_t ih_hcrc; /* Image Header CRC Checksum */
+ uint32_t ih_time; /* Image Creation Timestamp */
+ uint32_t ih_size; /* Image Data Size */
+ uint32_t ih_load; /* Data Load Address */
+ uint32_t ih_ep; /* Entry Point Address */
+ uint32_t ih_dcrc; /* Image Data CRC Checksum */
+ uint8_t ih_os; /* Operating System */
+ uint8_t ih_arch; /* CPU architecture */
+ uint8_t ih_type; /* Image Type */
+ uint8_t ih_comp; /* Compression Type */
+ uint8_t ih_name[IH_NMLEN]; /* Image Name */
+} image_header_t;
--- /dev/null
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#pragma once
+
+void start(void);
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+
+#pragma once
+
+#include <stdint.h>
+
+/*
+ * Low-level I/O routines.
+ *
+ * Copied from <file:arch/powerpc/include/asm/io.h> (which has no copyright)
+ */
+static inline uint8_t in_8(const volatile uint8_t *addr)
+{
+ int ret;
+
+ __asm__ __volatile__("lbz%U1%X1 %0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "m" (*addr));
+ return ret;
+}
+
+static inline void out_8(volatile uint8_t *addr, uint8_t val)
+{
+ __asm__ __volatile__("stb%U0%X0 %1,%0; sync"
+ : "=m" (*addr) : "r" (val));
+}
+
+static inline uint16_t in_le16(const volatile uint16_t *addr)
+{
+ uint32_t ret;
+
+ __asm__ __volatile__("lhbrx %0,0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "r" (addr), "m" (*addr));
+
+ return ret;
+}
+
+static inline uint16_t in_be16(const volatile uint16_t *addr)
+{
+ uint32_t ret;
+
+ __asm__ __volatile__("lhz%U1%X1 %0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "m" (*addr));
+ return ret;
+}
+
+static inline void out_le16(volatile uint16_t *addr, uint16_t val)
+{
+ __asm__ __volatile__("sthbrx %1,0,%2; sync" : "=m" (*addr)
+ : "r" (val), "r" (addr));
+}
+
+static inline void out_be16(volatile uint16_t *addr, uint16_t val)
+{
+ __asm__ __volatile__("sth%U0%X0 %1,%0; sync"
+ : "=m" (*addr) : "r" (val));
+}
+
+static inline uint32_t in_le32(const volatile uint32_t *addr)
+{
+ uint32_t ret;
+
+ __asm__ __volatile__("lwbrx %0,0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "r" (addr), "m" (*addr));
+ return ret;
+}
+
+static inline uint32_t in_be32(const volatile uint32_t *addr)
+{
+ uint32_t ret;
+
+ __asm__ __volatile__("lwz%U1%X1 %0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "m" (*addr));
+ return ret;
+}
+
+static inline void out_le32(volatile uint32_t *addr, uint32_t val)
+{
+ __asm__ __volatile__("stwbrx %1,0,%2; sync" : "=m" (*addr)
+ : "r" (val), "r" (addr));
+}
+
+static inline void out_be32(volatile uint32_t *addr, uint32_t val)
+{
+ __asm__ __volatile__("stw%U0%X0 %1,%0; sync"
+ : "=m" (*addr) : "r" (val));
+}
+
+static inline void sync(void)
+{
+ asm volatile("sync" : : : "memory");
+}
+
+static inline void eieio(void)
+{
+ asm volatile("eieio" : : : "memory");
+}
+
+static inline void barrier(void)
+{
+ asm volatile("" : : : "memory");
+}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+/*
+ *
+ * Definitions used by various bits of low-level assembly code on PowerPC.
+ *
+ * Copyright (C) 1995-1999 Gary Thomas, Paul Mackerras, Cort Dougan.
+ */
+
+/* Condition Register Bit Fields */
+
+#define cr0 0
+#define cr1 1
+#define cr2 2
+#define cr3 3
+#define cr4 4
+#define cr5 5
+#define cr6 6
+#define cr7 7
+
+/* General Purpose Registers (GPRs) */
+
+#define r0 0
+#define r1 1
+#define r2 2
+#define r3 3
+#define r4 4
+#define r5 5
+#define r6 6
+#define r7 7
+#define r8 8
+#define r9 9
+#define r10 10
+#define r11 11
+#define r12 12
+#define r13 13
+#define r14 14
+#define r15 15
+#define r16 16
+#define r17 17
+#define r18 18
+#define r19 19
+#define r20 20
+#define r21 21
+#define r22 22
+#define r23 23
+#define r24 24
+#define r25 25
+#define r26 26
+#define r27 27
+#define r28 28
+#define r29 29
+#define r30 30
+#define r31 31
--- /dev/null
+// SPDX-License-Identifier: BSD-2-Clause
+
+#pragma once
+
+int serial_console_getchar(void);
+int serial_console_tstc(void);
+void serial_console_putchar(char c);
+void serial_console_init(void);
+
--- /dev/null
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#pragma once
+
+#include <types.h>
+
+int spi_nor_read_id(void);
+int spi_nor_read_data(void *dest, size_t pos, size_t len);
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Common SPI Interface: Controller-specific definitions
+ *
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ *
+ * Based on U-boot's spi.h:
+ *
+ * (C) Copyright 2001
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
+ */
+
+#pragma once
+
+#include <types.h>
+
+/* SPI mode flags */
+#define SPI_CPHA BIT(0) /* clock phase (1 = SPI_CLOCK_PHASE_SECOND) */
+#define SPI_CPOL BIT(1) /* clock polarity (1 = SPI_POLARITY_HIGH) */
+#define SPI_MODE_0 (0|0) /* (original MicroWire) */
+#define SPI_MODE_1 (0|SPI_CPHA)
+#define SPI_MODE_2 (SPI_CPOL|0)
+#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
+
+struct spi_transfer {
+ const void *tx_buf;
+ void *rx_buf;
+ size_t len;
+};
+
+static inline size_t spi_message_len(const struct spi_transfer *msg, int n) {
+ size_t total = 0;
+ for (int i = 0; i < n; i++) {
+ total += msg[i].len;
+ }
+ return total;
+}
+
+int spi_init(unsigned int cs, unsigned int max_hz, unsigned int mode);
+int spi_claim_bus(void);
+void spi_release_bus(void);
+int spi_xfer(const struct spi_transfer *msg, int n);
+size_t spi_max_xfer(void);
--- /dev/null
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#pragma once
+
+#include <serial.h>
+#include <types.h>
+
+static inline int getchar(void)
+{
+ return serial_console_getchar();
+}
+
+static inline int tstc(void)
+{
+ return serial_console_tstc();
+}
+
+static inline int putchar(char c)
+{
+ if (c == '\n')
+ serial_console_putchar('\r');
+ serial_console_putchar(c);
+ return 0;
+}
+
+int puts(const char *s);
+
+/* Utility functions */
+void put_u4(uint8_t v);
+void put_u8(uint8_t v);
+void put_u16(uint16_t v);
+void put_u32(uint32_t v);
+void put_ptr(const void *p);
+void put_array(const void *p, size_t l);
+
+#define put_with_label(label, put, value) do { \
+ puts(label); \
+ put(value); \
+ puts("\n"); \
+ } while (0)
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+
+#pragma once
+
+#include <stddef.h>
+
+extern char *strcpy(char *dest, const char *src);
+extern char *strncpy(char *dest, const char *src, size_t n);
+extern char *strcat(char *dest, const char *src);
+extern char *strchr(const char *s, int c);
+extern char *strrchr(const char *s, int c);
+extern int strcmp(const char *s1, const char *s2);
+extern int strncmp(const char *s1, const char *s2, size_t n);
+extern size_t strlen(const char *s);
+extern size_t strnlen(const char *s, size_t count);
+
+extern void *memset(void *s, int c, size_t n);
+extern void *memmove(void *dest, const void *src, unsigned long n);
+extern void *memcpy(void *dest, const void *src, unsigned long n);
+extern void *memchr(const void *s, int c, size_t n);
+extern int memcmp(const void *s1, const void *s2, size_t n);
+
+extern void flush_cache(void *, unsigned long);
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Code originates from Linux kernel arch/powerpc/boot
+ * (types.h, swab.h, of.h)
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+#define BIT(nr) (1UL << (nr))
+
+#define min(x,y) ({ \
+ typeof(x) _x = (x); \
+ typeof(y) _y = (y); \
+ (void) (&_x == &_y); \
+ _x < _y ? _x : _y; })
+
+#define max(x,y) ({ \
+ typeof(x) _x = (x); \
+ typeof(y) _y = (y); \
+ (void) (&_x == &_y); \
+ _x > _y ? _x : _y; })
+
+#define min_t(type, a, b) min(((type) a), ((type) b))
+#define max_t(type, a, b) max(((type) a), ((type) b))
+
+static inline uint16_t swab16(uint16_t x)
+{
+ return ((x & (uint16_t)0x00ffU) << 8) |
+ ((x & (uint16_t)0xff00U) >> 8);
+}
+
+static inline uint32_t swab32(uint32_t x)
+{
+ return ((x & (uint32_t)0x000000ffUL) << 24) |
+ ((x & (uint32_t)0x0000ff00UL) << 8) |
+ ((x & (uint32_t)0x00ff0000UL) >> 8) |
+ ((x & (uint32_t)0xff000000UL) >> 24);
+}
+
+static inline uint64_t swab64(uint64_t x)
+{
+ return (uint64_t)((x & (uint64_t)0x00000000000000ffULL) << 56) |
+ (uint64_t)((x & (uint64_t)0x000000000000ff00ULL) << 40) |
+ (uint64_t)((x & (uint64_t)0x0000000000ff0000ULL) << 24) |
+ (uint64_t)((x & (uint64_t)0x00000000ff000000ULL) << 8) |
+ (uint64_t)((x & (uint64_t)0x000000ff00000000ULL) >> 8) |
+ (uint64_t)((x & (uint64_t)0x0000ff0000000000ULL) >> 24) |
+ (uint64_t)((x & (uint64_t)0x00ff000000000000ULL) >> 40) |
+ (uint64_t)((x & (uint64_t)0xff00000000000000ULL) >> 56);
+}
+
+#ifdef __LITTLE_ENDIAN__
+#define cpu_to_be16(x) swab16(x)
+#define be16_to_cpu(x) swab16(x)
+#define cpu_to_be32(x) swab32(x)
+#define be32_to_cpu(x) swab32(x)
+#define cpu_to_be64(x) swab64(x)
+#define be64_to_cpu(x) swab64(x)
+#else
+#define cpu_to_be16(x) (x)
+#define be16_to_cpu(x) (x)
+#define cpu_to_be32(x) (x)
+#define be32_to_cpu(x) (x)
+#define cpu_to_be64(x) (x)
+#define be64_to_cpu(x) (x)
+#endif
--- /dev/null
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#include <image.h>
+#include <init.h>
+#include <spi.h>
+#include <spi-nor.h>
+#include <stdio.h>
+#include <string.h>
+
+static bool check_image_header(const image_header_t *header)
+{
+ if (header->ih_magic != cpu_to_be32(IH_MAGIC_OKLI)) {
+ puts("Invalid image magic\n");
+ return false;
+ }
+
+ if (header->ih_comp != cpu_to_be32(IH_COMP_NONE)) {
+ puts("Unsupported compressed image\n");
+ return false;
+ }
+
+ return true;
+}
+
+static uint32_t do_load(void)
+{
+ image_header_t header;
+ uint32_t ih_size, ih_load, ih_ep;
+
+ if (spi_nor_read_id())
+ return UINT32_MAX;
+
+ puts("Reading image header...\n");
+ if (spi_nor_read_data(&header, CONFIG_IMAGE_OFFSET, sizeof(header)))
+ return UINT32_MAX;
+
+ if (!check_image_header(&header))
+ return UINT32_MAX;
+
+ header.ih_name[sizeof(header.ih_name) - 1] = 0;
+ ih_size = be32_to_cpu(header.ih_size);
+ ih_load = be32_to_cpu(header.ih_load);
+ ih_ep = be32_to_cpu(header.ih_ep);
+
+ put_with_label("Image Name: ", puts, (const char *)header.ih_name);
+ put_with_label("Data Size: ", put_u32, ih_size);
+ put_with_label("Load Address: ", put_u32, ih_load);
+ put_with_label("Entry Point: ", put_u32, ih_ep);
+
+ puts("Reading image data...\n");
+ void *loadaddr = (void *)ih_load;
+ if (spi_nor_read_data(loadaddr, CONFIG_IMAGE_OFFSET + sizeof(header),
+ ih_size))
+ return false;
+
+ flush_cache(loadaddr, ih_size);
+
+ return ih_ep;
+}
+
+static void enter_image(uint32_t addr)
+{
+ typedef void (*entry_t)(void);
+ entry_t entry = (entry_t)addr;
+
+ puts("Starting image...\n");
+ entry();
+}
+
+static void load(void)
+{
+ uint32_t addr;
+ int ret;
+
+ ret = spi_init(0, CONFIG_SPI_MAX_HZ, SPI_MODE_0);
+ if (ret) {
+ puts("Failed to initialize SPI controller\n");
+ return;
+ }
+
+ ret = spi_claim_bus();
+ if (ret) {
+ puts("Failed to enable SPI controller\n");
+ return;
+ }
+
+ addr = do_load();
+
+ spi_release_bus();
+
+ if (addr != UINT32_MAX)
+ enter_image(addr);
+}
+
+void start(void)
+{
+ serial_console_init();
+ puts("=== " CONFIG_PROGRAM_NAME " ===\n");
+
+ load();
+
+ puts("Halting execution.\n");
+ while (true) {}
+}
--- /dev/null
+OUTPUT_ARCH(powerpc:common)
+ENTRY(_start)
+EXTERN(_start)
+SECTIONS {
+ .text :
+ {
+ _text_start = .;
+ *(.text*)
+ _text_len = ABSOLUTE(. - _text_start);
+ }
+ .data :
+ {
+ _data_start = .;
+ *(.rodata*)
+ *(.data*)
+ *(.sdata*)
+ _data_len = ABSOLUTE(. - _data_start);
+ }
+ . = ALIGN(4096);
+ .bss :
+ {
+ _bss_start = .;
+ . += 4K;
+ _stack_top = .;
+ *(.bss*)
+ *(.sbss*)
+ _bss_len = ABSOLUTE(. - _bss_start);
+ }
+ . = ALIGN(4096);
+ _end = .;
+}
--- /dev/null
+// 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');
+}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) Paul Mackerras 1997.
+ *
+ * NOTE: this code runs in 32 bit mode and is packaged as ELF32.
+ */
+
+#include <ppc_asm.h>
+
+ .text
+ .globl strcpy
+strcpy:
+ addi r5,r3,-1
+ addi r4,r4,-1
+1: lbzu r0,1(r4)
+ cmpwi 0,r0,0
+ stbu r0,1(r5)
+ bne 1b
+ blr
+
+ .globl strncpy
+strncpy:
+ cmpwi 0,r5,0
+ beqlr
+ mtctr r5
+ addi r6,r3,-1
+ addi r4,r4,-1
+1: lbzu r0,1(r4)
+ cmpwi 0,r0,0
+ stbu r0,1(r6)
+ bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */
+ blr
+
+ .globl strcat
+strcat:
+ addi r5,r3,-1
+ addi r4,r4,-1
+1: lbzu r0,1(r5)
+ cmpwi 0,r0,0
+ bne 1b
+ addi r5,r5,-1
+1: lbzu r0,1(r4)
+ cmpwi 0,r0,0
+ stbu r0,1(r5)
+ bne 1b
+ blr
+
+ .globl strchr
+strchr:
+ addi r3,r3,-1
+1: lbzu r0,1(r3)
+ cmpw 0,r0,r4
+ beqlr
+ cmpwi 0,r0,0
+ bne 1b
+ li r3,0
+ blr
+
+ .globl strcmp
+strcmp:
+ addi r5,r3,-1
+ addi r4,r4,-1
+1: lbzu r3,1(r5)
+ cmpwi 1,r3,0
+ lbzu r0,1(r4)
+ subf. r3,r0,r3
+ beqlr 1
+ beq 1b
+ blr
+
+ .globl strncmp
+strncmp:
+ mtctr r5
+ addi r5,r3,-1
+ addi r4,r4,-1
+1: lbzu r3,1(r5)
+ cmpwi 1,r3,0
+ lbzu r0,1(r4)
+ subf. r3,r0,r3
+ beqlr 1
+ bdnzt eq,1b
+ blr
+
+ .globl strlen
+strlen:
+ addi r4,r3,-1
+1: lbzu r0,1(r4)
+ cmpwi 0,r0,0
+ bne 1b
+ subf r3,r3,r4
+ blr
+
+ .globl memset
+memset:
+ rlwimi r4,r4,8,16,23
+ rlwimi r4,r4,16,0,15
+ addi r6,r3,-4
+ cmplwi 0,r5,4
+ blt 7f
+ stwu r4,4(r6)
+ beqlr
+ andi. r0,r6,3
+ add r5,r0,r5
+ subf r6,r0,r6
+ rlwinm r0,r5,32-2,2,31
+ mtctr r0
+ bdz 6f
+1: stwu r4,4(r6)
+ bdnz 1b
+6: andi. r5,r5,3
+7: cmpwi 0,r5,0
+ beqlr
+ mtctr r5
+ addi r6,r6,3
+8: stbu r4,1(r6)
+ bdnz 8b
+ blr
+
+ .globl memmove
+memmove:
+ cmplw 0,r3,r4
+ bgt backwards_memcpy
+ /* fall through */
+
+ .globl memcpy
+memcpy:
+ rlwinm. r7,r5,32-3,3,31 /* r7 = r5 >> 3 */
+ addi r6,r3,-4
+ addi r4,r4,-4
+ beq 3f /* if less than 8 bytes to do */
+ andi. r0,r6,3 /* get dest word aligned */
+ mtctr r7
+ bne 5f
+ andi. r0,r4,3 /* check src word aligned too */
+ bne 3f
+1: lwz r7,4(r4)
+ lwzu r8,8(r4)
+ stw r7,4(r6)
+ stwu r8,8(r6)
+ bdnz 1b
+ andi. r5,r5,7
+2: cmplwi 0,r5,4
+ blt 3f
+ lwzu r0,4(r4)
+ addi r5,r5,-4
+ stwu r0,4(r6)
+3: cmpwi 0,r5,0
+ beqlr
+ mtctr r5
+ addi r4,r4,3
+ addi r6,r6,3
+4: lbzu r0,1(r4)
+ stbu r0,1(r6)
+ bdnz 4b
+ blr
+5: subfic r0,r0,4
+ cmpw cr1,r0,r5
+ add r7,r0,r4
+ andi. r7,r7,3 /* will source be word-aligned too? */
+ ble cr1,3b
+ bne 3b /* do byte-by-byte if not */
+ mtctr r0
+6: lbz r7,4(r4)
+ addi r4,r4,1
+ stb r7,4(r6)
+ addi r6,r6,1
+ bdnz 6b
+ subf r5,r0,r5
+ rlwinm. r7,r5,32-3,3,31
+ beq 2b
+ mtctr r7
+ b 1b
+
+ .globl backwards_memcpy
+backwards_memcpy:
+ rlwinm. r7,r5,32-3,3,31 /* r7 = r5 >> 3 */
+ add r6,r3,r5
+ add r4,r4,r5
+ beq 3f
+ andi. r0,r6,3
+ mtctr r7
+ bne 5f
+ andi. r0,r4,3
+ bne 3f
+1: lwz r7,-4(r4)
+ lwzu r8,-8(r4)
+ stw r7,-4(r6)
+ stwu r8,-8(r6)
+ bdnz 1b
+ andi. r5,r5,7
+2: cmplwi 0,r5,4
+ blt 3f
+ lwzu r0,-4(r4)
+ subi r5,r5,4
+ stwu r0,-4(r6)
+3: cmpwi 0,r5,0
+ beqlr
+ mtctr r5
+4: lbzu r0,-1(r4)
+ stbu r0,-1(r6)
+ bdnz 4b
+ blr
+5: cmpw cr1,r0,r5
+ subf r7,r0,r4
+ andi. r7,r7,3
+ ble cr1,3b
+ bne 3b
+ mtctr r0
+6: lbzu r7,-1(r4)
+ stbu r7,-1(r6)
+ bdnz 6b
+ subf r5,r0,r5
+ rlwinm. r7,r5,32-3,3,31
+ beq 2b
+ mtctr r7
+ b 1b
+
+ .globl memchr
+memchr:
+ cmpwi 0,r5,0
+ blelr
+ mtctr r5
+ addi r3,r3,-1
+1: lbzu r0,1(r3)
+ cmpw r0,r4
+ beqlr
+ bdnz 1b
+ li r3,0
+ blr
+
+ .globl memcmp
+memcmp:
+ cmpwi 0,r5,0
+ ble 2f
+ mtctr r5
+ addi r6,r3,-1
+ addi r4,r4,-1
+1: lbzu r3,1(r6)
+ lbzu r0,1(r4)
+ subf. r3,r0,r3
+ bdnzt 2,1b
+ blr
+2: li r3,0
+ blr
+
+
+/*
+ * Flush the dcache and invalidate the icache for a range of addresses.
+ *
+ * flush_cache(addr, len)
+ */
+ .global flush_cache
+flush_cache:
+ addi 4,4,0x1f /* len = (len + 0x1f) / 0x20 */
+ rlwinm. 4,4,27,5,31
+ mtctr 4
+ beqlr
+1: dcbf 0,3
+ icbi 0,3
+ addi 3,3,0x20
+ bdnz 1b
+ sync
+ isync
+ blr
+