From 1af7591e37d09ddcd734ea07d0e999cf61c8bc5e Mon Sep 17 00:00:00 2001
From: vetch <vetch97@gmail.com>
Date: Mon, 13 Jan 2020 12:40:38 +0100
Subject: Great Reorganisation, modify structure and makefile

---
 src/arm/PL1/kernel/demo_functionality.c | 121 ++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 src/arm/PL1/kernel/demo_functionality.c

(limited to 'src/arm/PL1/kernel/demo_functionality.c')

diff --git a/src/arm/PL1/kernel/demo_functionality.c b/src/arm/PL1/kernel/demo_functionality.c
new file mode 100644
index 0000000..217a858
--- /dev/null
+++ b/src/arm/PL1/kernel/demo_functionality.c
@@ -0,0 +1,121 @@
+#include "io.h"
+#include "psr.h"
+#include "memory.h"
+#include "translation_table_descriptors.h"
+#include "ramfs.h"
+#include "strings.h"
+#include "paging.h"
+#include "armclock.h"
+#include "scheduler.h"
+
+void demo_paging_support(void)
+{
+  uint32_t ID_MMFR0;
+  // get contents of coprocessor register to check for paging support
+  asm("mrc p15, 0, %0, c0, c1, 4" : "=r" (ID_MMFR0));
+  
+  char *paging;
+  
+  switch(ID_MMFR0 & 0xf) /* lowest 4 bits indicate VMSA support */
+    {
+    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 ?_?";
+    }
+  
+  puts(paging);
+}
+
+void demo_current_mode(void)
+{
+
+  // get content of current program status register to check the current
+  // processor mode (should be system, as we set it in boot.S)
+  PSR_t CPSR = read_CPSR();
+
+  char *mode_name;
+  
+  switch(CPSR.fields.PSR_MODE_4_0)
+    {
+    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;
+    }
+
+  prints("current mode: ");
+  puts(mode_name);
+}
+
+#define TRANSLATION_TABLE					     \
+  ((short_section_descriptor_t volatile*) TRANSLATION_TABLE_BASE)
+
+extern char
+  _binary_ramfs_img_start,
+  _binary_ramfs_img_end,
+  _binary_ramfs_img_size;
+
+void __attribute__((noreturn)) demo_setup_PL0(void)
+{
+  // find PL_0_test.img im ramfs
+  struct ramfile PL_0_test_img;
+
+  if (find_file(&_binary_ramfs_img_start, "PL_0_test.img",
+		&PL_0_test_img))
+    {
+      puts("PL_0_test.img not found :(");
+      asm volatile ("wfi");
+    }
+
+  // dummy value 5 for now, as we haven't implemented processes yet  
+  uint16_t physical_section_number = claim_and_map_section
+    ((void*) 5, PL0_SECTION_NUMBER, AP_2_0_MODEL_RW_ALL);
+  
+  if (physical_section_number == SECTION_NULL)
+    {
+      puts("Couldn't claim memory section for unprivileged code :(");
+      while(1);
+    }
+  
+  size_t physical_section_start =
+    (((size_t) physical_section_number) << 20);
+    
+  // check that translation works... by copying a string using one
+  // mapping and reading it using other :D
+  char str_part1[] = "mapped section for PL0 code (0x";
+  char str_part2[] = " -> 0x";
+  char str_part3[] = ")";
+
+  char *string_end = (char*) physical_section_start;
+
+  memcpy(string_end, str_part1, sizeof(str_part1) - 1);
+  uint32_to_hex(VIRTUAL_PL0_MEMORY_START,
+		string_end += sizeof(str_part1) - 1);
+  memcpy(string_end += 8, str_part2, sizeof(str_part2) - 1);
+  uint32_to_hex(physical_section_start,
+		string_end += sizeof(str_part2) - 1);
+  memcpy(string_end += 8, str_part3, sizeof(str_part3));
+
+  puts((char*) VIRTUAL_PL0_MEMORY_START);
+
+  // now paste a userspace program to that section
+  memcpy((void*) VIRTUAL_PL0_MEMORY_START,
+	 PL_0_test_img.file_contents, PL_0_test_img.file_size);
+
+  puts("copied PL0 code to it's section");
+
+  puts("All ready! scheduling!");
+
+  schedule_new(VIRTUAL_PL0_MEMORY_START, // the new pc
+	       VIRTUAL_PL0_MEMORY_END);  // the new sp
+}
-- 
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