rp2040: Add rp2350 bootrom based chipid and reboot to bootloader code

This adds the bootrom code needed to implement "reboot into
bootloader" and "chipid" capabilities.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 59 insertions, 0 deletions

diff --git a/src/rp2040/rp2350_bootrom.c b/src/rp2040/rp2350_bootrom.c
new file mode 100644
index 00000000..257fb3d4
--- /dev/null
+++ b/src/rp2040/rp2350_bootrom.c
@@ -0,0 +1,59 @@
+// Code for interacting with bootrom on rp235x chips
+//
+// Copyright (C) 2024  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include <stdint.h> // uint32_t
+#include "boot/picoboot_constants.h" // REBOOT2_FLAG_REBOOT_TYPE_BOOTSEL
+#include "hardware/address_mapped.h" // static_assert
+#include "internal.h" // bootrom_read_unique_id
+#include "pico/bootrom_constants.h" // RT_FLAG_FUNC_ARM_NONSEC
+
+static void *
+rom_func_lookup(uint32_t code)
+{
+    typedef void *(*rom_table_lookup_fn)(uint32_t code, uint32_t mask);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+    rom_table_lookup_fn rom_table_lookup = (rom_table_lookup_fn)
+        (uintptr_t)*(uint16_t*)(BOOTROM_TABLE_LOOKUP_OFFSET);
+#pragma GCC diagnostic pop
+    return rom_table_lookup(code, RT_FLAG_FUNC_ARM_SEC);
+}
+
+
+/****************************************************************
+ * Reboot to USB rom bootloader
+ ****************************************************************/
+
+void
+bootrom_reboot_usb_bootloader(void)
+{
+    typedef int (*rom_reboot_fn)(uint32_t flags, uint32_t delay_ms
+                                 , uint32_t p0, uint32_t p1);
+    rom_reboot_fn func = rom_func_lookup(ROM_FUNC_REBOOT);
+    func(REBOOT2_FLAG_REBOOT_TYPE_BOOTSEL | REBOOT2_FLAG_NO_RETURN_ON_SUCCESS
+         , 10, 0, 0);
+}
+
+
+/****************************************************************
+ * Unique id reading
+ ****************************************************************/
+
+#define PICO_UNIQUE_BOARD_ID_SIZE_BYTES 8
+
+void
+bootrom_read_unique_id(uint8_t *out, uint32_t maxlen)
+{
+    typedef int (*rom_get_sys_info_fn)(uint8_t *out_buffer
+                                       , uint32_t out_buffer_word_size
+                                       , uint32_t flags);
+    rom_get_sys_info_fn func = rom_func_lookup(ROM_FUNC_GET_SYS_INFO);
+    uint8_t data[9 * 4];
+    func(data, 9, SYS_INFO_CHIP_INFO);
+    int i;
+    for (i = 0; i < PICO_UNIQUE_BOARD_ID_SIZE_BYTES; i++)
+        out[i] = data[PICO_UNIQUE_BOARD_ID_SIZE_BYTES - 1 + 2 * 4 - i];
+}