Added mailbox system

include/gpio.h

@@ -1,5 +1,10 @@
 #include "stdint.h"
 
+enum
+{
+    PERIPHERAL_BASE = 0xFE000000
+};
+
 // Functions for peeking/poking into memory
 void     poke(int64_t addr, uint32_t val);
 uint32_t peek(int64_t addr);

include/mb.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include "stdint.h"
+
+uint32_t get_vc_firmware_rev(void);
+uint8_t* get_board_mac_address(uint8_t* buffer);

src/gpio.c

@@ -12,8 +12,6 @@ uint32_t peek(int64_t addr)
 
 enum
 {
-    PERIPHERAL_BASE =                   0xFE000000,
-
     GPFSEL0         = PERIPHERAL_BASE + 0x200000,
     GPSET0          = PERIPHERAL_BASE + 0x20001C,
     GPCLR0          = PERIPHERAL_BASE + 0x200028,

src/kernel.c

@@ -2,6 +2,7 @@
 #include "convert.h"
 #include "string.h"
 #include "memory.h"
+#include "mb.h"
 
 void print_clippy();
 char* get_user_input(char* buffer);
@@ -10,12 +11,28 @@ void main()
 {
     extern long _start;
     char buffer[1024];
+    uint8_t mac_address[6];
 
     uart_init();
     heap_init();
 
     print_clippy();
     uart_puts("Boot successful! \n");
+
+    uart_puts("Firmware revision: ");
+    uart_puts(utoa(get_vc_firmware_rev(), buffer, 10));
+
+    get_board_mac_address(mac_address);
+    uart_puts("\nMAC Address: ");
+    for(uint8_t i = 0; i < 6; i++)
+    {
+        uart_puts(utoa(mac_address[i], buffer, 16));
+        if(i != 5)
+            uart_puts(":");
+    }
+    uart_puts("\n");
+    
+    uart_puts("\n");
     uart_puts("Started execution at 0x");
     uart_puts(ultoa((long)&_start, buffer, 16));
 

src/mb.c

@@ -0,0 +1,121 @@
+#include "mb.h"
+#include "gpio.h"
+#include "memory.h"
+#include "io.h"
+#include "convert.h"
+
+volatile uint32_t __attribute__((aligned(16))) mailbox[36];
+
+enum
+{
+    VIDEOCORE_MAILBOX   = (PERIPHERAL_BASE + 0x0000B880),
+    MAILBOX_READ        = (VIDEOCORE_MAILBOX + 0x0),
+    MAILBOX_POLL        = (VIDEOCORE_MAILBOX + 0x10),
+    MAILBOX_SENDER      = (VIDEOCORE_MAILBOX + 0x14),
+    MAILBOX_STATUS      = (VIDEOCORE_MAILBOX + 0x18),
+    MAILBOX_CONFIG      = (VIDEOCORE_MAILBOX + 0x1C),
+    MAILBOX_WRITE       = (VIDEOCORE_MAILBOX + 0x20),
+
+    MAILBOX_RESPONSE    = 0x80000000,
+    MAILBOX_FULL        = 0x80000000,
+    MAILBOX_EMPTY       = 0x40000000
+};
+
+struct BufferHeader
+{
+    uint32_t size;
+    uint32_t status_code;
+};
+
+struct TagHeader
+{
+    uint32_t identifier;
+    uint32_t buf_size;
+    uint32_t status_code;
+};
+
+uint32_t mailbox_call(uint8_t ch)
+{
+    uint32_t r = ((uint32_t)((int64_t)&mailbox) & ~0xF) | (ch & 0xF);
+
+    while(peek(MAILBOX_STATUS) & MAILBOX_FULL);
+
+    poke(MAILBOX_WRITE, r);
+
+    for(;;)
+    {
+        while(peek(MAILBOX_STATUS) & MAILBOX_EMPTY);
+
+        if(r == peek(MAILBOX_READ))
+            return mailbox[1] == MAILBOX_RESPONSE;
+    }
+
+    return 0;
+}
+
+struct BufferHeader* alloc_buffer()
+{
+    return (struct BufferHeader*)malloc();
+}
+
+void free_buffer(struct BufferHeader* ptr)
+{
+    free((void*)ptr);
+}
+
+uint8_t* create_tag(uint8_t* ptr, uint32_t identifier, uint8_t* buffer, uint32_t size)
+{
+    struct TagHeader* header = (struct TagHeader*)ptr;
+    header->identifier = identifier;
+    header->buf_size = size;
+    header->status_code = 0;
+
+    ptr = (uint8_t*)(header + 1);
+    for(uint32_t i = 0; i < size; i++)
+    {
+        *ptr++ = *buffer++;
+    }
+
+    uint8_t padding = size % 4;
+    if(padding)
+        ptr += 4 - padding;
+
+    return ptr;
+}
+
+uint32_t get_vc_firmware_rev(void)
+{
+    mailbox[0] = 7 * sizeof(uint32_t);  // buffer size
+    mailbox[1] = 0;     // request code
+    mailbox[2] = 1;     // tag identifier
+    mailbox[3] = sizeof(uint32_t);     // tag buffer size
+    mailbox[4] = 0;     // tag request code
+    mailbox[5] = 0;     // tag content
+    mailbox[6] = 0;     // end tag
+
+    mailbox_call(8);
+
+    return mailbox[5];
+}
+
+uint8_t* get_board_mac_address(uint8_t* buffer)
+{
+    mailbox[0] = 8 * sizeof(uint32_t);  // buffer size
+    mailbox[1] = 0;     // request code
+    mailbox[2] = 0x00010003;     // tag identifier
+    mailbox[3] = 6 * sizeof(uint8_t);     // tag buffer size
+    mailbox[4] = 0;     // tag request code
+
+    mailbox[5] = 0;     // tag content
+    mailbox[6] = 0;
+
+    mailbox[7] = 0;     // end tag
+
+    mailbox_call(8);
+
+    uint8_t* mac_address = (uint8_t*)(mailbox + 5);
+    for(uint8_t i = 0; i < 6; i++)
+        buffer[i] = mac_address[i];
+
+    return buffer;
+}