From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Thu, 11 Jun 2020 09:15:31 +0000 (+0200)
Subject: bios/boot: make SDCard boot more flexible using a boot.json file on the SDCard.
X-Git-Tag: 24jan2021_ls180~186
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c2ae22eeb6350726664161487a6532fe79d46174;p=litex.git

bios/boot: make SDCard boot more flexible using a boot.json file on the SDCard.

The BIOS now reads the boot.json file to know which files need to be copied to RAM and where.
It will fallback to boot.bin is no boot.json is found and boot will fail if neither is found.

Example of boot.json file used to boot Linux-On-LiteX-Vexriscv:
{
	"Image":        "0x40000000",
	"rootfs.cpio":  "0x40800000",
	"rv32.dtb":     "0x41000000",
	"emulator.bin": "0x41100000"
}
---

diff --git a/litex/soc/software/bios/boot.c b/litex/soc/software/bios/boot.c
index 18ad01b9..cf445eec 100644
--- a/litex/soc/software/bios/boot.c
+++ b/litex/soc/software/bios/boot.c
@@ -9,6 +9,7 @@
 
 #include <stdio.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <console.h>
 #include <uart.h>
 #include <system.h>
@@ -22,6 +23,7 @@
 
 #include "sfl.h"
 #include "boot.h"
+#include "jsmn.h"
 
 #include <progress.h>
 #include <spiflash.h>
@@ -109,7 +111,7 @@ static uint32_t get_uint32(unsigned char* data)
 	return ((uint32_t) data[0] << 24) |
 		   ((uint32_t) data[1] << 16) |
 		   ((uint32_t) data[2] << 8) |
-		    (uint32_t) data[3];
+			(uint32_t) data[3];
 }
 
 #define MAX_FAILED 5
@@ -551,7 +553,7 @@ void romboot(void)
 
 #if defined(CSR_SPISDCARD_BASE) || defined(CSR_SDCORE_BASE)
 
-static int copy_image_from_sdcard_to_ram(const char * filename, unsigned int ram_address)
+static int copy_file_from_sdcard_to_ram(const char * filename, unsigned int ram_address)
 {
 	FRESULT fr;
 	FATFS fs;
@@ -596,11 +598,79 @@ static int copy_image_from_sdcard_to_ram(const char * filename, unsigned int ram
 	return 1;
 }
 
-void sdcardboot(void)
+static void sdcardboot_from_json(const char * filename)
 {
+	FRESULT fr;
+	FATFS fs;
+	FIL file;
+
+	uint8_t i;
+	uint8_t count;
+	uint32_t length;
+	uint32_t result;
+
+	/* FIXME: modify/increase if too limiting */
+	char json_buffer[256];
+	char image_filename[32];
+	char image_address[32];
+	uint8_t image_found;
+
+	/* Read JSON file */
+	fr = f_mount(&fs, "", 1);
+	if (fr != FR_OK)
+		return;
+	fr = f_open(&file, filename, FA_READ);
+	if (fr != FR_OK) {
+		printf("%s file not found.\n", filename);
+		f_mount(0, "", 0);
+		return;
+	}
+
+	fr = f_read(&file, json_buffer, sizeof(json_buffer), &length);
 
+	/* Close JSON file */
+	f_close(&file);
+	f_mount(0, "", 0);
+
+	/* Parse JSON file */
+	jsmntok_t t[16];
+	jsmn_parser p;
+	jsmn_init(&p);
+	image_found = 0;
+	count = jsmn_parse(&p, json_buffer, strlen(json_buffer), t, sizeof(t)/sizeof(*t));
+	for (i=0; i<count-1; i++) {
+		/* Images are JSON strings with 1 children */
+		if ((t[i].type == JSMN_STRING) && (t[i].size == 1)) {
+			/* Get Image filename */
+			memset(image_filename, 0, sizeof(image_filename));
+			memcpy(image_filename, json_buffer+t[i].start,   t[i].end   - t[i].start);
+			/* Get Image address */
+			memset(image_address,  0, sizeof(image_address));
+			memcpy(image_address,  json_buffer+t[i+1].start, t[i+1].end - t[i+1].start);
+			/* Copy Image from SDCard to address */
+			result = copy_file_from_sdcard_to_ram(image_filename, strtoul(image_address, NULL, 0));
+			if (result == 0)
+				return;
+			image_found = 1;
+		}
+	}
+
+	/* Boot to last Image address */
+	if (image_found)
+		boot(0, 0, 0, strtoul(image_address, NULL, 0));
+}
+
+static void sdcardboot_from_bin(const char * filename)
+{
 	uint32_t result;
+	result = copy_file_from_sdcard_to_ram(filename, MAIN_RAM_BASE);
+	if (result == 0)
+		return;
+	boot(0, 0, 0, MAIN_RAM_BASE);
+}
 
+void sdcardboot(void)
+{
 #ifdef CSR_SPISDCARD_BASE
 	printf("Booting from SDCard in SPI-Mode...\n");
 #endif
@@ -608,47 +678,15 @@ void sdcardboot(void)
 	printf("Booting from SDCard in SD-Mode...\n");
 #endif
 
-	/* Copy files to RAM */
-#if defined(CONFIG_CPU_TYPE_VEXRISCV) && defined(CONFIG_CPU_VARIANT_LINUX)
-	printf("Loading Linux images from SDCard to RAM...\n");
-	result = copy_image_from_sdcard_to_ram("rv32.dtb", MAIN_RAM_BASE + DEVICE_TREE_IMAGE_RAM_OFFSET);
-	if (result)
-		result &= copy_image_from_sdcard_to_ram("emulator.bin", MAIN_RAM_BASE + EMULATOR_IMAGE_RAM_OFFSET);
-	if (result)
-		result &= copy_image_from_sdcard_to_ram("Image", MAIN_RAM_BASE + KERNEL_IMAGE_RAM_OFFSET);
-	if (result)
-		result &= copy_image_from_sdcard_to_ram("rootfs.cpio", MAIN_RAM_BASE + ROOTFS_IMAGE_RAM_OFFSET);
-	if (result)
-		boot(0, 0, 0, MAIN_RAM_BASE + EMULATOR_IMAGE_RAM_OFFSET);
-	printf("Unable to load all Linux images, falling back to boot.bin...\n");
-#endif
+	/* Boot from boot.json */
+	printf("Booting from boot.json...\n");
+	sdcardboot_from_json("boot.json");
 
-#if defined(CONFIG_CPU_TYPE_VEXRISCV) && \
-	(defined(CONFIG_CPU_VARIANT_1C)   || \
-	 defined(CONFIG_CPU_VARIANT_2C)   || \
-	 defined(CONFIG_CPU_VARIANT_4C)   || \
-	 defined(CONFIG_CPU_VARIANT_8C)   || \
-	 defined(CONFIG_CPU_VARIANT_MP1C) || \
-	 defined(CONFIG_CPU_VARIANT_MP2C) || \
-	 defined(CONFIG_CPU_VARIANT_MP4C) || \
-	 defined(CONFIG_CPU_VARIANT_MP8C))
-	printf("Loading Linux images from SDCard to RAM...\n");
-	result = copy_image_from_sdcard_to_ram("Image", 0x40000000);
-	if (result)
-		result &= copy_image_from_sdcard_to_ram("dtb", 0x40ef0000);
-	if (result)
-		result &= copy_image_from_sdcard_to_ram("rootfs.cpio", 0x41000000);
-	if (result)
-		result &= copy_image_from_sdcard_to_ram("fw_jump.bin", 0x40f00000);
-	if (result)
-		boot(0, 0, 0, 0x40f00000);
-	printf("Unable to load all Linux images, falling back to boot.bin...\n");
-#endif
+	/* Boot from boot.bin */
+	printf("Booting from boot.bin...\n");
+	sdcardboot_from_bin("boot.bin");
 
-	result = copy_image_from_sdcard_to_ram("boot.bin", MAIN_RAM_BASE);
-	if(result)
-		boot(0, 0, 0, MAIN_RAM_BASE);
-	else
-		printf("SDCard boot failed.\n");
+	/* Boot failed if we are here... */
+	printf("SDCard boot failed.\n");
 }
 #endif
diff --git a/litex/soc/software/include/base/jsmn.h b/litex/soc/software/include/base/jsmn.h
new file mode 100644
index 00000000..3178dcc9
--- /dev/null
+++ b/litex/soc/software/include/base/jsmn.h
@@ -0,0 +1,471 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2010 Serge Zaitsev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef JSMN_H
+#define JSMN_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef JSMN_STATIC
+#define JSMN_API static
+#else
+#define JSMN_API extern
+#endif
+
+/**
+ * JSON type identifier. Basic types are:
+ * 	o Object
+ * 	o Array
+ * 	o String
+ * 	o Other primitive: number, boolean (true/false) or null
+ */
+typedef enum {
+  JSMN_UNDEFINED = 0,
+  JSMN_OBJECT = 1,
+  JSMN_ARRAY = 2,
+  JSMN_STRING = 3,
+  JSMN_PRIMITIVE = 4
+} jsmntype_t;
+
+enum jsmnerr {
+  /* Not enough tokens were provided */
+  JSMN_ERROR_NOMEM = -1,
+  /* Invalid character inside JSON string */
+  JSMN_ERROR_INVAL = -2,
+  /* The string is not a full JSON packet, more bytes expected */
+  JSMN_ERROR_PART = -3
+};
+
+/**
+ * JSON token description.
+ * type		type (object, array, string etc.)
+ * start	start position in JSON data string
+ * end		end position in JSON data string
+ */
+typedef struct jsmntok {
+  jsmntype_t type;
+  int start;
+  int end;
+  int size;
+#ifdef JSMN_PARENT_LINKS
+  int parent;
+#endif
+} jsmntok_t;
+
+/**
+ * JSON parser. Contains an array of token blocks available. Also stores
+ * the string being parsed now and current position in that string.
+ */
+typedef struct jsmn_parser {
+  unsigned int pos;     /* offset in the JSON string */
+  unsigned int toknext; /* next token to allocate */
+  int toksuper;         /* superior token node, e.g. parent object or array */
+} jsmn_parser;
+
+/**
+ * Create JSON parser over an array of tokens
+ */
+JSMN_API void jsmn_init(jsmn_parser *parser);
+
+/**
+ * Run JSON parser. It parses a JSON data string into and array of tokens, each
+ * describing
+ * a single JSON object.
+ */
+JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len,
+                        jsmntok_t *tokens, const unsigned int num_tokens);
+
+#ifndef JSMN_HEADER
+/**
+ * Allocates a fresh unused token from the token pool.
+ */
+static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser, jsmntok_t *tokens,
+                                   const size_t num_tokens) {
+  jsmntok_t *tok;
+  if (parser->toknext >= num_tokens) {
+    return NULL;
+  }
+  tok = &tokens[parser->toknext++];
+  tok->start = tok->end = -1;
+  tok->size = 0;
+#ifdef JSMN_PARENT_LINKS
+  tok->parent = -1;
+#endif
+  return tok;
+}
+
+/**
+ * Fills token type and boundaries.
+ */
+static void jsmn_fill_token(jsmntok_t *token, const jsmntype_t type,
+                            const int start, const int end) {
+  token->type = type;
+  token->start = start;
+  token->end = end;
+  token->size = 0;
+}
+
+/**
+ * Fills next available token with JSON primitive.
+ */
+static int jsmn_parse_primitive(jsmn_parser *parser, const char *js,
+                                const size_t len, jsmntok_t *tokens,
+                                const size_t num_tokens) {
+  jsmntok_t *token;
+  int start;
+
+  start = parser->pos;
+
+  for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+    switch (js[parser->pos]) {
+#ifndef JSMN_STRICT
+    /* In strict mode primitive must be followed by "," or "}" or "]" */
+    case ':':
+#endif
+    case '\t':
+    case '\r':
+    case '\n':
+    case ' ':
+    case ',':
+    case ']':
+    case '}':
+      goto found;
+    default:
+                   /* to quiet a warning from gcc*/
+      break;
+    }
+    if (js[parser->pos] < 32 || js[parser->pos] >= 127) {
+      parser->pos = start;
+      return JSMN_ERROR_INVAL;
+    }
+  }
+#ifdef JSMN_STRICT
+  /* In strict mode primitive must be followed by a comma/object/array */
+  parser->pos = start;
+  return JSMN_ERROR_PART;
+#endif
+
+found:
+  if (tokens == NULL) {
+    parser->pos--;
+    return 0;
+  }
+  token = jsmn_alloc_token(parser, tokens, num_tokens);
+  if (token == NULL) {
+    parser->pos = start;
+    return JSMN_ERROR_NOMEM;
+  }
+  jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+  token->parent = parser->toksuper;
+#endif
+  parser->pos--;
+  return 0;
+}
+
+/**
+ * Fills next token with JSON string.
+ */
+static int jsmn_parse_string(jsmn_parser *parser, const char *js,
+                             const size_t len, jsmntok_t *tokens,
+                             const size_t num_tokens) {
+  jsmntok_t *token;
+
+  int start = parser->pos;
+
+  parser->pos++;
+
+  /* Skip starting quote */
+  for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+    char c = js[parser->pos];
+
+    /* Quote: end of string */
+    if (c == '\"') {
+      if (tokens == NULL) {
+        return 0;
+      }
+      token = jsmn_alloc_token(parser, tokens, num_tokens);
+      if (token == NULL) {
+        parser->pos = start;
+        return JSMN_ERROR_NOMEM;
+      }
+      jsmn_fill_token(token, JSMN_STRING, start + 1, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+      token->parent = parser->toksuper;
+#endif
+      return 0;
+    }
+
+    /* Backslash: Quoted symbol expected */
+    if (c == '\\' && parser->pos + 1 < len) {
+      int i;
+      parser->pos++;
+      switch (js[parser->pos]) {
+      /* Allowed escaped symbols */
+      case '\"':
+      case '/':
+      case '\\':
+      case 'b':
+      case 'f':
+      case 'r':
+      case 'n':
+      case 't':
+        break;
+      /* Allows escaped symbol \uXXXX */
+      case 'u':
+        parser->pos++;
+        for (i = 0; i < 4 && parser->pos < len && js[parser->pos] != '\0';
+             i++) {
+          /* If it isn't a hex character we have an error */
+          if (!((js[parser->pos] >= 48 && js[parser->pos] <= 57) ||   /* 0-9 */
+                (js[parser->pos] >= 65 && js[parser->pos] <= 70) ||   /* A-F */
+                (js[parser->pos] >= 97 && js[parser->pos] <= 102))) { /* a-f */
+            parser->pos = start;
+            return JSMN_ERROR_INVAL;
+          }
+          parser->pos++;
+        }
+        parser->pos--;
+        break;
+      /* Unexpected symbol */
+      default:
+        parser->pos = start;
+        return JSMN_ERROR_INVAL;
+      }
+    }
+  }
+  parser->pos = start;
+  return JSMN_ERROR_PART;
+}
+
+/**
+ * Parse JSON string and fill tokens.
+ */
+JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len,
+                        jsmntok_t *tokens, const unsigned int num_tokens) {
+  int r;
+  int i;
+  jsmntok_t *token;
+  int count = parser->toknext;
+
+  for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+    char c;
+    jsmntype_t type;
+
+    c = js[parser->pos];
+    switch (c) {
+    case '{':
+    case '[':
+      count++;
+      if (tokens == NULL) {
+        break;
+      }
+      token = jsmn_alloc_token(parser, tokens, num_tokens);
+      if (token == NULL) {
+        return JSMN_ERROR_NOMEM;
+      }
+      if (parser->toksuper != -1) {
+        jsmntok_t *t = &tokens[parser->toksuper];
+#ifdef JSMN_STRICT
+        /* In strict mode an object or array can't become a key */
+        if (t->type == JSMN_OBJECT) {
+          return JSMN_ERROR_INVAL;
+        }
+#endif
+        t->size++;
+#ifdef JSMN_PARENT_LINKS
+        token->parent = parser->toksuper;
+#endif
+      }
+      token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY);
+      token->start = parser->pos;
+      parser->toksuper = parser->toknext - 1;
+      break;
+    case '}':
+    case ']':
+      if (tokens == NULL) {
+        break;
+      }
+      type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY);
+#ifdef JSMN_PARENT_LINKS
+      if (parser->toknext < 1) {
+        return JSMN_ERROR_INVAL;
+      }
+      token = &tokens[parser->toknext - 1];
+      for (;;) {
+        if (token->start != -1 && token->end == -1) {
+          if (token->type != type) {
+            return JSMN_ERROR_INVAL;
+          }
+          token->end = parser->pos + 1;
+          parser->toksuper = token->parent;
+          break;
+        }
+        if (token->parent == -1) {
+          if (token->type != type || parser->toksuper == -1) {
+            return JSMN_ERROR_INVAL;
+          }
+          break;
+        }
+        token = &tokens[token->parent];
+      }
+#else
+      for (i = parser->toknext - 1; i >= 0; i--) {
+        token = &tokens[i];
+        if (token->start != -1 && token->end == -1) {
+          if (token->type != type) {
+            return JSMN_ERROR_INVAL;
+          }
+          parser->toksuper = -1;
+          token->end = parser->pos + 1;
+          break;
+        }
+      }
+      /* Error if unmatched closing bracket */
+      if (i == -1) {
+        return JSMN_ERROR_INVAL;
+      }
+      for (; i >= 0; i--) {
+        token = &tokens[i];
+        if (token->start != -1 && token->end == -1) {
+          parser->toksuper = i;
+          break;
+        }
+      }
+#endif
+      break;
+    case '\"':
+      r = jsmn_parse_string(parser, js, len, tokens, num_tokens);
+      if (r < 0) {
+        return r;
+      }
+      count++;
+      if (parser->toksuper != -1 && tokens != NULL) {
+        tokens[parser->toksuper].size++;
+      }
+      break;
+    case '\t':
+    case '\r':
+    case '\n':
+    case ' ':
+      break;
+    case ':':
+      parser->toksuper = parser->toknext - 1;
+      break;
+    case ',':
+      if (tokens != NULL && parser->toksuper != -1 &&
+          tokens[parser->toksuper].type != JSMN_ARRAY &&
+          tokens[parser->toksuper].type != JSMN_OBJECT) {
+#ifdef JSMN_PARENT_LINKS
+        parser->toksuper = tokens[parser->toksuper].parent;
+#else
+        for (i = parser->toknext - 1; i >= 0; i--) {
+          if (tokens[i].type == JSMN_ARRAY || tokens[i].type == JSMN_OBJECT) {
+            if (tokens[i].start != -1 && tokens[i].end == -1) {
+              parser->toksuper = i;
+              break;
+            }
+          }
+        }
+#endif
+      }
+      break;
+#ifdef JSMN_STRICT
+    /* In strict mode primitives are: numbers and booleans */
+    case '-':
+    case '0':
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9':
+    case 't':
+    case 'f':
+    case 'n':
+      /* And they must not be keys of the object */
+      if (tokens != NULL && parser->toksuper != -1) {
+        const jsmntok_t *t = &tokens[parser->toksuper];
+        if (t->type == JSMN_OBJECT ||
+            (t->type == JSMN_STRING && t->size != 0)) {
+          return JSMN_ERROR_INVAL;
+        }
+      }
+#else
+    /* In non-strict mode every unquoted value is a primitive */
+    default:
+#endif
+      r = jsmn_parse_primitive(parser, js, len, tokens, num_tokens);
+      if (r < 0) {
+        return r;
+      }
+      count++;
+      if (parser->toksuper != -1 && tokens != NULL) {
+        tokens[parser->toksuper].size++;
+      }
+      break;
+
+#ifdef JSMN_STRICT
+    /* Unexpected char in strict mode */
+    default:
+      return JSMN_ERROR_INVAL;
+#endif
+    }
+  }
+
+  if (tokens != NULL) {
+    for (i = parser->toknext - 1; i >= 0; i--) {
+      /* Unmatched opened object or array */
+      if (tokens[i].start != -1 && tokens[i].end == -1) {
+        return JSMN_ERROR_PART;
+      }
+    }
+  }
+
+  return count;
+}
+
+/**
+ * Creates a new parser based over a given buffer with an array of tokens
+ * available.
+ */
+JSMN_API void jsmn_init(jsmn_parser *parser) {
+  parser->pos = 0;
+  parser->toknext = 0;
+  parser->toksuper = -1;
+}
+
+#endif /* JSMN_HEADER */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* JSMN_H */