io api rework

16 files changed, 258 insertions, 103 deletions

diff --git a/Makefile b/Makefile
index c3fc2f1..1e8f8fe 100644
--- a/Makefile
+++ b/Makefile
@@ -3,9 +3,11 @@ ELFFLAGS=-nostdlib -lgcc
 
 ARM_OBJECTS=kernel.o paging.o demo_functionality.o PL0_test.o uart.o loader_stage1.o loader_stage2.o
 
-KERNEL_STAGE2_OBJECTS=setup.o interrupt_vector.o interrupts.o uart.o demo_functionality.o paging.o ramfs_embeddable.o ramfs.o
+KERNEL_STAGE2_OBJECTS=setup.o interrupt_vector.o interrupts.o uart.o demo_functionality.o paging.o ramfs_embeddable.o ramfs.o strings.o io.o
 
-PL_0_TEST_OBJECTS=PL0_utils.o svc.o PL0_test.o
+PL_0_TEST_OBJECTS=PL0_utils.o svc.o PL0_test.o strings.o io.o
+
+LOADER_STAGE2_OBJECTS=uart.o strings.o io.o loader_stage2.o
 
 RAMFS_FILES=PL_0_test.img
 
@@ -41,8 +43,8 @@ kernel_stage2.elf : kernel_stage2.ld $(KERNEL_STAGE2_OBJECTS)
 #kernel.elf : boot.o kernel.o uart.o demo_functionality.o paging.o interrupt_vector.o interrupts.o ramfs_embeddable.o ramfs.o
 #	arm-none-eabi-gcc -T linker.ld -o $@ $(ELFFLAGS) $^
 
-loader_stage2.elf : loader_stage2.o uart.o
-	arm-none-eabi-gcc -T loader_stage2_linker.ld -o $@ $(ELFFLAGS) $^
+loader_stage2.elf : loader_stage2_linker.ld $(LOADER_STAGE2_OBJECTS)
+	arm-none-eabi-gcc -T $< -o $@ $(ELFFLAGS) $(LOADER_STAGE2_OBJECTS)
 
 loader_stage1.o : loader_stage1.S  loader_stage2.img
 	arm-none-eabi-as -mcpu=cortex-a7 $< -o $@
diff --git a/PL0_test.c b/PL0_test.c
index f476eb7..ac74ad4 100644
--- a/PL0_test.c
+++ b/PL0_test.c
@@ -15,15 +15,15 @@ void PL0_main(void)
   first_kernel_byte[0] = *(char*) 0x0;
   first_kernel_byte[1] = '\0';
 
-  uart_puts(first_kernel_byte);
+  puts(first_kernel_byte);
     
   while (1)
     {
       char c = getchar();
-
-      putchar(c);
       
       if (c == '\r')
 	putchar('\n');
+
+      putchar(c);
     }
 }
diff --git a/PL0_utils.c b/PL0_utils.c
index 2cede90..d83edb9 100644
--- a/PL0_utils.c
+++ b/PL0_utils.c
@@ -2,26 +2,18 @@
 #include <stdint.h>
 
 #include "svc_interface.h"
+#include "PL0_utils.h"
 
 // most generic definition possible
 // the actual function defined in svc.S
 uint32_t svc(enum svc_type, ...);
 
-void putchar(int character)
+void putchar(char character)
 {
   svc(UART_PUTCHAR, character);
 }
 
-int getchar(void)
+char getchar(void)
 {
   return svc(UART_GETCHAR);
 }
-
-void puts(char *string)
-{
-  for (size_t i = 0; string[i]; i++)
-    putchar(string[i]);
-
-  putchar('\n');
-  putchar('\r');
-}
diff --git a/PL0_utils.h b/PL0_utils.h
index ba72fd3..c26a100 100644
--- a/PL0_utils.h
+++ b/PL0_utils.h
@@ -1,10 +1,6 @@
 #ifndef PL0_UTILS_H
 #define PL0_UTILS_H
 
-void putchar(int character);
-
-int getchar(void);
-
-void puts(char *string);
+#include "io.h"
 
 #endif // PL0_UTILS_H
diff --git a/demo_functionality.c b/demo_functionality.c
index d8fbdb5..2db40f8 100644
--- a/demo_functionality.c
+++ b/demo_functionality.c
@@ -1,4 +1,4 @@
-#include "uart.h"
+#include "io.h"
 #include "psr.h"
 #include "memory.h"
 #include "translation_table_descriptors.h"
@@ -14,16 +14,16 @@ void demo_paging_support(void)
   
   switch(ID_MMFR0 & 0xf) /* lowest 4 bits indicate VMSA support */
     {
-    case 0 : paging = "no paging\n\r"; break;
-    case 1 : paging = "implementation defined paging\n\r"; break;
-    case 2 : paging = "VMSAv6, with cache and TLB type registers\n\r"; break;
-    case 3 : paging = "VMSAv7, with support for remapping and access flag\n\r"; break;
-    case 4 : paging = "VMSAv7 with PXN bit supported\n\r"; break;
-    case 5 : paging = "VMSAv7, PXN and long format descriptors. EPAE is supported.\n\r"; break;
-    default : paging = "?_? unknown paging ?_?\n\r";
+    case 0 : paging = "no paging"; break;
+    case 1 : paging = "implementation defined paging"; break;
+    case 2 : paging = "VMSAv6, with cache and TLB type registers"; break;
+    case 3 : paging = "VMSAv7, with support for remapping and access flag"; break;
+    case 4 : paging = "VMSAv7 with PXN bit supported"; break;
+    case 5 : paging = "VMSAv7, PXN and long format descriptors. EPAE is supported."; break;
+    default : paging = "?_? unknown paging ?_?";
     }
   
-  uart_puts(paging);
+  puts(paging);
 }
 
 void demo_current_mode(void)
@@ -37,20 +37,20 @@ void demo_current_mode(void)
   
   switch(CPSR.fields.PSR_MODE_4_0)
     {
-    case MODE_USER       : mode_name = "User (PL0)\r\n"; break;
-    case MODE_FIQ        : mode_name = "FIQ (PL1)\r\n"; break;
-    case MODE_IRQ        : mode_name = "IRQ (PL1)\r\n"; break;
-    case MODE_SUPERVISOR : mode_name = "Supervisor (PL1)\r\n"; break;
-    case MODE_MONITOR    : mode_name = "Monitor (PL1)\r\n"; break;
-    case MODE_ABORT      : mode_name = "Abort (PL1)\r\n"; break;
-    case MODE_HYPERVISOR : mode_name = "Hyp (PL2)\r\n"; break;
-    case MODE_UNDEFINED  : mode_name = "Undefined (PL1)\r\n"; break;
-    case MODE_SYSTEM     : mode_name = "System (PL1)\r\n"; break;
-    default : mode_name = "Unknown mode\r\n"; break;
+    case MODE_USER       : mode_name = "User (PL0)"; break;
+    case MODE_FIQ        : mode_name = "FIQ (PL1)"; break;
+    case MODE_IRQ        : mode_name = "IRQ (PL1)"; break;
+    case MODE_SUPERVISOR : mode_name = "Supervisor (PL1)"; break;
+    case MODE_MONITOR    : mode_name = "Monitor (PL1)"; break;
+    case MODE_ABORT      : mode_name = "Abort (PL1)"; break;
+    case MODE_HYPERVISOR : mode_name = "Hyp (PL2)"; break;
+    case MODE_UNDEFINED  : mode_name = "Undefined (PL1)"; break;
+    case MODE_SYSTEM     : mode_name = "System (PL1)"; break;
+    default : mode_name = "Unknown mode"; break;
     }
 
-  uart_puts("current mode: ");
-  uart_puts(mode_name);
+  prints("current mode: ");
+  puts(mode_name);
 }
 
 #define TRANSLATION_TABLE					     \
@@ -69,7 +69,7 @@ void demo_setup_PL0(void)
   if (find_file(&_binary_ramfs_img_start, "PL_0_test.img",
 		&PL_0_test_img))
     {
-      uart_puts("PL_0_test.img not found :(\r\n");
+      puts("PL_0_test.img not found :(");
       asm volatile ("wfi");
     }
 
@@ -96,20 +96,20 @@ void demo_setup_PL0(void)
   
   // check that translation works... by copying a string using one
   // mapping and reading it using other :D
-  char message[] = "mapped sections for PL0 code\n\r";
+  char message[] = "mapped sections for PL0 code";
   
   unsigned int i;
   for (i = 0; i < sizeof(message); i++)
     ((volatile char*) UNPRIVILEGED_MEMORY_START)[i] = message[i];
   
-  uart_puts((char*) VIRTUAL_PL0_MEMORY_START);
+  puts((char*) VIRTUAL_PL0_MEMORY_START);
 
   // now paste a userspace program to that section
   for (uint32_t i = 0; i < PL_0_test_img.file_size; i++)
     ((volatile char*) VIRTUAL_PL0_MEMORY_START)[i] =
       PL_0_test_img.file_contents[i];
 
-  uart_puts("copied PL0 code to it's section\n\r");
+  puts("copied PL0 code to it's section");
 }
 
 // needed for array initialization in demo_go_unprivileged()
@@ -132,7 +132,7 @@ void demo_go_unprivileged(void)
   new_SPSR.fields.PSR_MODE_4_0 = MODE_USER;
   write_SPSR(new_SPSR);
 
-  uart_puts("All ready, jumping to PL0 code\n\r");
+  puts("All ready, jumping to PL0 code");
 
   asm volatile("cps %[sysmode]\n\r"
 	       "mov sp, %[stackaddr]\n\r"
diff --git a/interrupts.c b/interrupts.c
index f47bc1d..3102761 100644
--- a/interrupts.c
+++ b/interrupts.c
@@ -1,4 +1,4 @@
-#include "uart.h"
+#include "io.h"
 #include "svc_interface.h"
 
 void setup(void);
@@ -18,7 +18,7 @@ void reset_handler(void)
 
 void undefined_instruction_vector(void)
 {
-    uart_puts("Undefined instruction occured");
+    puts("Undefined instruction occured");
     while( 1 )
     {
         /* Do Nothing! */
@@ -32,16 +32,16 @@ uint32_t supervisor_call_handler(enum svc_type request, uint32_t arg1,
   
   switch(request) {
   case UART_PUTCHAR:
-    uart_putc(arg1);
+    putchar(arg1);
     break;
   case UART_GETCHAR:
-    return uart_getc();
+    return getchar();
   case UART_WRITE:
-    uart_puts("UART_WRITE not implemented!!!!!\n\r");
+    puts("UART_WRITE not implemented!!!!!");
     break;
   default:
     // perhaps we should kill the process now?
-    uart_puts("unknown supervisor call type!!!!!\n\r");
+    puts("unknown supervisor call type!!!!!");
   }
 
   return 0; // a dummy value
@@ -49,28 +49,28 @@ uint32_t supervisor_call_handler(enum svc_type request, uint32_t arg1,
 
 void abort_handler(void)
 {
-  uart_puts("re-entered system\n\r");
+  puts("re-entered system");
 
   while(1);
 }
 
 void generic_handler(void)
 {
-  uart_puts("something weird happened\n\r");
+  puts("something weird happened");
 
   while(1);
 }
 
 void irq_handler(void)
 {
-  uart_puts("irq happened\n\r");
+  puts("irq happened");
 
   while(1);
 }
 
 void fiq_handler(void)
 {
-  uart_puts("fiq happened\n\r");
+  puts("fiq happened");
 
   while(1);
 }
diff --git a/io.c b/io.c
new file mode 100644
index 0000000..f35fda9
--- /dev/null
+++ b/io.c
@@ -0,0 +1,64 @@
+#include <stddef.h>
+
+#include "io.h"
+#include "strings.h"
+
+void puts(char string[])
+{
+  prints(string);
+
+  putchar('\n');
+  putchar('\r');
+}
+
+void prints(char string[])
+{
+  for (size_t i = 0; string[i]; i++)
+    putchar(string[i]);
+}
+
+void printdec(uint32_t number)
+{
+  char buf[11];
+
+  uint32_to_decstring(number, buf);
+
+  prints(buf);
+}
+
+void printhex(uint32_t number)
+{
+  char buf[9];
+
+  uint32_to_hexstring(number, buf);
+
+  prints(buf);
+}
+
+void printbin(uint32_t number)
+{
+  char buf[33];
+
+  uint32_to_binstring(number, buf);
+
+  prints(buf);
+}
+
+void printdect(uint32_t number)
+{
+  char buf[11];
+
+  uint32_to_decstringt(number, buf);
+
+  prints(buf);
+}
+
+void printhext(uint32_t number)
+{
+  char buf[9];
+
+  uint32_to_hexstringt(number, buf);
+
+  prints(buf);
+}
+
diff --git a/io.h b/io.h
new file mode 100644
index 0000000..161728a
--- /dev/null
+++ b/io.h
@@ -0,0 +1,26 @@
+#ifndef IO_H
+#define IO_H
+
+#include <stdint.h>
+
+// putchar() and getchar() are not part of io.c, but it's useful to
+// have those symbols declared here
+void putchar(char c);
+
+char getchar(void);
+
+void puts(char string[]);
+
+void prints(char string[]);
+
+void printdec(uint32_t number);
+
+void printhex(uint32_t number);
+
+void printbin(uint32_t number);
+
+void printdect(uint32_t number);
+
+void printhext(uint32_t number);
+
+#endif // IO_H
diff --git a/loader_stage2.c b/loader_stage2.c
index f49d94c..e05de51 100644
--- a/loader_stage2.c
+++ b/loader_stage2.c
@@ -1,6 +1,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <uart.h>
+#include <io.h>
 #include <global.h>
 
 void *const kernel_load_addr = ((void*) 0x8000);
@@ -17,10 +18,10 @@ void _stage2_main(uint32_t r0, uint32_t r1, uint32_t atags)
   // get kernel size via uart (little endian)
   uint32_t b0, b1, b2, b3;
   
-  b0 = uart_getc();
-  b1 = uart_getc();
-  b2 = uart_getc();
-  b3 = uart_getc();
+  b0 = getchar();
+  b1 = getchar();
+  b2 = getchar();
+  b3 = getchar();
   
   uint32_t kernel_size = b0 | (b1 << 8) | (b2 << 16) | (b3 << 24);
 
@@ -28,7 +29,7 @@ void _stage2_main(uint32_t r0, uint32_t r1, uint32_t atags)
   char *dst = kernel_load_addr, *end = dst + kernel_size;
 
   while (dst < end)
-    *(dst++) = uart_getc();
+    *(dst++) = getchar();
 
   // jump to kernel
   ((void(*)(uint32_t, uint32_t, uint32_t)) kernel_load_addr)
diff --git a/memory.h b/memory.h
index adc3bc0..f6ece42 100644
--- a/memory.h
+++ b/memory.h
@@ -1,6 +1,8 @@
 #ifndef MEMORY_H
 #define MEMORY_H
 
+#include <stddef.h>
+
 // These macros were heavily used b4 I moved all the address
 // computation to the linker script. Now I'm just keeping them
 // in case they're needed for something else :)
diff --git a/paging.c b/paging.c
index 7c2a9de..2985e7e 100644
--- a/paging.c
+++ b/paging.c
@@ -1,24 +1,21 @@
 #include "cp_regs.h"
-#include "uart.h"
 #include "strings.h"
 #include "memory.h"
 #include "translation_table_descriptors.h"
+#include "io.h"
 
 void setup_flat_map(void)
 {
-  char bits[33]; // for printing uint32_t bit values
-  
   // compute translation table base address
   // translation table shall start at first 2^14-bytes aligned
   // address after the kernel image
 
-  uint32_to_bits(TRANSLATION_TABLE_BASE, bits);
-  uart_puts("binary representation of chosen"
-	    " lvl1 translation table address: ");
-  uart_puts(bits); uart_puts("\n\r");
+  prints("chosen lvl1 translation table address: 0x");
+  printhex(TRANSLATION_TABLE_BASE);
+  puts("");
  
   // flat map all memory
-  uart_puts("preparing translation table\n\r");
+  puts("preparing translation table");
   short_descriptor_lvl1_t volatile *translation_table =
     (short_descriptor_lvl1_t*) TRANSLATION_TABLE_BASE;
   
@@ -35,8 +32,7 @@ void setup_flat_map(void)
       };
 
   // meddle with domain settings
-  uart_puts("setting domain0 to client access"
-	    " and blocking other domains\n\r");
+  puts("setting domain0 to client access and blocking other domains");
 
   DACR_t DACR = 0;
   DACR = set_domain_permissions(DACR, 0, DOMAIN_CLIENT_ACCESS);
@@ -55,7 +51,7 @@ void setup_flat_map(void)
   // we also disable data and instruction caches and the MMU
   
   // some of this is redundant (i.e. MMU should already be disabled)
-  uart_puts("setting C, I, AFE and TRE to 0 in SCTLR\n\r");
+  puts("setting C, I, AFE and TRE to 0 in SCTLR");
 
   SCTLR_t SCTLR;
   asm("mrc p15, 0, %0, c1, c0, 0" : "=r" (SCTLR.raw));
@@ -70,8 +66,8 @@ void setup_flat_map(void)
 
   // TODO: move invalidation instructions to some header as inlines
   
-  uart_puts("invalidating instruction cache, branch prediction,"
-	    " and entire main TLB\n\r");
+  puts("invalidating instruction cache, branch prediction,"
+       " and entire main TLB");
   
   // invalidate instruction cache
   asm("mcr p15, 0, r0, c7, c5, 0\n\r" // r0 gets ignored
@@ -86,8 +82,7 @@ void setup_flat_map(void)
       "isb" :: "r" (0) : "memory");
 
   // now set TTBCR to use TTBR0 exclusively
-  uart_puts("Setting TTBCR.N to 0, so that"
-	    " TTBR0 is used everywhere\n\r");
+  puts("Setting TTBCR.N to 0, so that TTBR0 is used everywhere");
   
   uint32_t TTBCR = 0;
   asm("mcr p15, 0, %0, c2, c0, 2" :: "r" (TTBCR));
@@ -102,7 +97,7 @@ void setup_flat_map(void)
   asm("mcr p15, 0, %0, c2, c0, 0" :: "r" (TTBR0.raw));
 
   // enable MMU
-  uart_puts("enabling the MMU\n\r");
+  puts("enabling the MMU");
 
   // redundant - we already have SCTLR contents in the variable
   // asm("mrc p15, 0, %0, c1, c0, 0" : "=r" (SCTLR.raw));
diff --git a/setup.c b/setup.c
index 48df825..3542043 100644
--- a/setup.c
+++ b/setup.c
@@ -1,4 +1,5 @@
 #include "uart.h"
+#include "io.h"
 #include "demo_functionality.h"
 #include "paging.h"
 
@@ -9,9 +10,9 @@ void setup(void)
   // When we attach screen session after loading kernel with socat
   // we miss kernel's greeting... So we'll make the kernel wait for
   // one char we're going to send from within screen
-  uart_getc();
+  getchar();
   
-  uart_puts("Hello, kernel World!\r\n");
+  puts("Hello, kernel World!");
 
   // prints some info
   demo_paging_support();
@@ -31,11 +32,11 @@ void setup(void)
   
   while (1)
     {
-      char c = uart_getc();
+      char c = getchar();
 
-      uart_putc(c);
-      
       if (c == '\r')
-	uart_putc('\n');
+	putchar('\n');
+
+      putchar(c);
     }
 }
diff --git a/strings.c b/strings.c
new file mode 100644
index 0000000..55aff97
--- /dev/null
+++ b/strings.c
@@ -0,0 +1,73 @@
+#include <stddef.h>
+
+#include "strings.h"
+
+void uint32_to_dec(uint32_t number, char buf[10])
+{
+  for (int i = 0; i < 10; i++)
+    {
+      buf[10 - 1 - i] = number % 10;
+      number /= 10;
+    }
+}
+
+void uint32_to_hex(uint32_t number, char buf[8])
+{
+  for (int i = 0; i < 8; i++)
+    {
+      unsigned char quadbit = (number >> ((8 - i - 1) * 4)) & 0xf;
+      buf[i] =  quadbit > 9 ? quadbit - 10 + 'a' : quadbit + '0';
+    }
+}
+
+void uint32_to_bin(uint32_t number, char buf[32])
+{
+  for (int i = 0; i < 32; i++)
+    buf[i] = ((number >> (32 - i - 1)) & 1) ? '1' : '0';
+}
+
+void uint32_to_decstring(uint32_t number, char buf[11])
+{
+  uint32_to_dec(number, buf);
+  buf[10] = '\0';
+}
+
+void uint32_to_hexstring(uint32_t number, char buf[9])
+{
+  uint32_to_hex(number, buf);
+  buf[9] = '\0';
+}
+
+void uint32_to_binstring(uint32_t number, char buf[33])
+{
+  uint32_to_bin(number, buf);
+  buf[32] = '\0';
+}
+
+void trim_0s(char string[])
+{
+  size_t i;
+  for (i = 0; string[i] != '\0' && string[i] != '0'; i++);
+
+  size_t j = 0;
+  
+  if (string[i] == '\0')
+    string[j++] = string[i--];
+
+  do
+    string[j] = string[i + j];
+  while (string[j++]);
+}
+
+void uint32_to_decstringt(uint32_t number, char buf[11])
+{
+  uint32_to_decstring(number, buf);
+  trim_0s(buf);
+}
+
+void uint32_to_hexstringt(uint32_t number, char buf[9])
+{
+  uint32_to_hexstring(number, buf);
+  trim_0s(buf);
+}
+
diff --git a/strings.h b/strings.h
index 8d4b511..bfe6fd0 100644
--- a/strings.h
+++ b/strings.h
@@ -3,12 +3,22 @@
 
 #include <stdint.h>
 
-static inline void uint32_to_bits(uint32_t number, char *buf)
-{
-  for (int i = 0; i < 32; i++)
-    buf[i] = ((number >> (32 - i - 1)) & 1) ? '1' : '0';
+void uint32_to_dec(uint32_t number, char buf[10]);
 
-  buf[32] = '\0';
-}
+void uint32_to_hex(uint32_t number, char buf[8]);
+
+void uint32_to_bin(uint32_t number, char buf[32]);
+
+void uint32_to_decstring(uint32_t number, char buf[11]);
+
+void uint32_to_hexstring(uint32_t number, char buf[9]);
+
+void uint32_to_binstring(uint32_t number, char buf[33]);
+
+void trim_0s(char string[]);
+
+void uint32_to_decstringt(uint32_t number, char buf[11]);
+
+void uint32_to_hexstringt(uint32_t number, char buf[9]);
 
 #endif // STRINGS_H
diff --git a/uart.c b/uart.c
index 139cfe0..2030538 100644
--- a/uart.c
+++ b/uart.c
@@ -63,22 +63,16 @@ void uart_init()
   mmio_write(UART0_CR, (1 << 0) | (1 << 8) | (1 << 9));
 }
 
-void uart_putc(unsigned char c)
+void putchar(char c)
 {
   // Wait for UART to become ready to transmit.
   while ( mmio_read(UART0_FR) & (1 << 5) ) { }
   mmio_write(UART0_DR, c);
 }
 
-unsigned char uart_getc()
+char getchar(void)
 {
   // Wait for UART to have received something.
   while ( mmio_read(UART0_FR) & (1 << 4) ) { }
   return mmio_read(UART0_DR);
 }
-
-void uart_puts(const char* str)
-{
-  for (size_t i = 0; str[i] != '\0'; i ++)
-    uart_putc((unsigned char)str[i]);
-}
diff --git a/uart.h b/uart.h
index ec29d47..d5e931b 100644
--- a/uart.h
+++ b/uart.h
@@ -39,8 +39,7 @@ enum
   };
 
 void uart_init();
-void uart_putc(unsigned char c);
-unsigned char uart_getc();
-void uart_puts(const char* str);
+void putchar(char c);
+char getchar(void);
 
 #endif // UART_H