fw: Add syscall TK1_SYSCALL_GET_APP_DATA

Add a new syscall to enable an app to get the data left for it by the
previous app in chain.

- Change testloadapp to leave some data for the next app to read.
- Call system call with:

  uint8_t next_app_data[RESET_DATA_SIZE];

  syscall(TK1_SYSCALL_GET_APP_DATA, (uint32_t)next_app_data, 0, 0);

hw/application_fpga/fw/testloadapp/main.c

@@ -154,7 +154,10 @@ void reset_from_client(void)
 
 	rst.type = START_CLIENT;
 
-	syscall(TK1_SYSCALL_RESET, (uint32_t)&rst, 0, 0);
+	// Give the next in chain something to look at.
+	memset(rst.next_app_data, 17, sizeof(rst.next_app_data));
+
+	syscall(TK1_SYSCALL_RESET, (uint32_t)&rst, sizeof(rst.next_app_data), 0);
 }
 
 int main(void)

hw/application_fpga/fw/tk1/main.c

@@ -444,7 +444,19 @@ static enum state start_where(struct context *ctx)
 {
 	assert(ctx != NULL);
 
-	// Where do we start? Read resetinfo 'startfrom'
+	debug_puts("resetinfo->type: ");
+	debug_putinthex(resetinfo->type);
+	debug_lf();
+
+	debug_puts("  ->app_digest: \n");
+	debug_hexdump(resetinfo->app_digest, RESET_DIGEST_SIZE);
+	debug_lf();
+
+	debug_puts("  ->next_app_data: \n");
+	debug_hexdump(resetinfo->next_app_data, RESET_DATA_SIZE);
+	debug_lf();
+
+	// Where do we start?
 	switch (resetinfo->type) {
 	case START_DEFAULT:
 		// fallthrough

hw/application_fpga/fw/tk1/mgmt_app.c

@@ -12,9 +12,9 @@
 //
 // To update this, compute the BLAKE2s digest of the app.bin
 static const uint8_t allowed_app_digest[32] = {
-    0xf8, 0x90, 0x34, 0x31, 0xe0, 0xed, 0xab, 0x8b, 0x91, 0xe5, 0x63,
-    0xe6, 0xea, 0x6a, 0x49, 0xe6, 0x53, 0x1e, 0xc7, 0x47, 0xca, 0x2f,
-    0x2b, 0x8f, 0xf3, 0x5e, 0x67, 0x13, 0x0f, 0xfa, 0x93, 0x36,
+    0x85, 0x29, 0xe3, 0x25, 0xf5, 0x8d, 0x53, 0x5f, 0xe1, 0x2a, 0x77,
+    0x92, 0xe7, 0xdc, 0x4b, 0x4d, 0x1,	0x85, 0x17, 0xca, 0xfd, 0x54,
+    0x83, 0xb3, 0xbb, 0x28, 0x4f, 0xa1, 0x98, 0x5f, 0x9e, 0x56,
 };
 
 static uint8_t current_app_digest[32];

hw/application_fpga/fw/tk1/reset.c

@@ -38,3 +38,21 @@ int reset(struct reset *userreset, size_t nextlen)
 
 	__builtin_unreachable();
 }
+
+int reset_data(uint8_t *next_app_data)
+{
+	if ((uint32_t)next_app_data < TK1_RAM_BASE ||
+	    (uint32_t)next_app_data >= TK1_RAM_BASE + TK1_RAM_SIZE) {
+		return -1;
+	}
+
+	if ((uint32_t)next_app_data + RESET_DATA_SIZE >
+	    TK1_RAM_BASE + TK1_RAM_SIZE) {
+		return -1;
+	}
+
+	memcpy(next_app_data, (void *)resetinfo->next_app_data,
+	       RESET_DATA_SIZE);
+
+	return 0;
+}

hw/application_fpga/fw/tk1/reset.h

@@ -9,6 +9,8 @@
 
 #define TK1_MMIO_RESETINFO_BASE 0xd0000f00
 #define TK1_MMIO_RESETINFO_SIZE 0x100
+#define RESET_DIGEST_SIZE 32
+#define RESET_DATA_SIZE 220
 
 enum reset_start {
 	START_DEFAULT = 0, // Probably cold boot
@@ -21,10 +23,11 @@ enum reset_start {
 };
 
 struct reset {
-	uint32_t type;		    // Reset type
-	uint8_t app_digest[32];	    // Program digest
-	uint8_t next_app_data[220]; // Data to leave around for next app
+	enum reset_start type;
+	uint8_t app_digest[RESET_DIGEST_SIZE];
+	uint8_t next_app_data[RESET_DATA_SIZE];
 };
 
 int reset(struct reset *userreset, size_t nextlen);
+int reset_data(uint8_t *next_app_data);
 #endif

hw/application_fpga/fw/tk1/syscall_handler.c

@@ -9,10 +9,9 @@
 
 #include "partition_table.h"
 #include "preload_app.h"
+#include "reset.h"
 #include "storage.h"
-
-#include "../tk1/reset.h"
-#include "../tk1/syscall_num.h"
+#include "syscall_num.h"
 
 // clang-format off
 static volatile uint32_t *udi           = (volatile uint32_t *)TK1_MMIO_TK1_UDI_FIRST;
@@ -100,6 +99,10 @@ int32_t syscall_handler(uint32_t number, uint32_t arg1, uint32_t arg2,
 	case TK1_SYSCALL_STATUS:
 		return part_get_status();
 
+	case TK1_SYSCALL_GET_APP_DATA:
+		// arg1 next_app_data
+		return reset_data((uint8_t *)arg1);
+
 	default:
 		assert(1 == 2);
 	}

hw/application_fpga/fw/tk1/syscall_num.h

@@ -18,6 +18,7 @@ enum syscall_num {
 	TK1_SYSCALL_PRELOAD_GET_DIGSIG = 11,
 	TK1_SYSCALL_REG_MGMT = 12,
 	TK1_SYSCALL_STATUS = 13,
+	TK1_SYSCALL_GET_APP_DATA = 14,
 };
 
 #endif