Complete rewrite of scratch to support IT5570

src/board/system76/lemp9/board.mk

@@ -19,6 +19,11 @@ CFLAGS+=-DI2C_DEBUGGER=0x76
 # Set battery I2C bus
 CFLAGS+=-DI2C_SMBUS=I2C_4
 
+# Set scratch ROM parameters
+SCRATCH_OFFSET=1024
+SCRATCH_SIZE=1024
+CFLAGS+=-DSCRATCH_OFFSET=$(SCRATCH_OFFSET) -DSCRATCH_SIZE=$(SCRATCH_SIZE)
+
 # Add scratch ROM source
 SCRATCH_DIR=$(BOARD_DIR)/scratch
 SCRATCH_SRC=$(wildcard $(SCRATCH_DIR)/*.c)

src/board/system76/lemp9/scratch.c

@@ -1,63 +1,28 @@
 #include <8051.h>
-#include <stdbool.h>
 #include <stdint.h>
 
 #include <common/macro.h>
 
-// Include scratch ROM, must be less than 4096 bytes, controlled by makefile
-uint8_t __code scratch_rom[] = {
+// Include scratch ROM
+uint8_t __code __at(SCRATCH_OFFSET) scratch_rom[] = {
     #include <scratch.h>
 };
 
-// Scratch RAM 0 is 4096 bytes, located at 0x0000 bytes
-volatile uint8_t __xdata __at(0x0000) scratch_ram[4096];
-
 volatile uint8_t __xdata __at(0x1040) SCAR0L;
 volatile uint8_t __xdata __at(0x1041) SCAR0M;
 volatile uint8_t __xdata __at(0x1042) SCAR0H;
 
-// Create new segment located at 0x1000, after scratch ROM mapping
-static void scratch_start(void) __naked {
-	__asm
-		.area SCRATCH (ABS,CODE)
-	__endasm;
-	__asm
-		.org 0x1000
-	__endasm;
-}
-
 // Enter or exit scratch ROM
 void scratch_trampoline(void) {
-    // Uses SCAR0 which is mapped at 0x0000 in data space and are
-    // 4096 bytes in size.
-
     // Disable interrupts
     EA = 0;
 
-    // Ensure pdata is not used!
-    int __data i;
-    // Copy scratch ROM
-    for (i = 0; i < ARRAY_SIZE(scratch_rom) && i < ARRAY_SIZE(scratch_ram); i++) {
-        scratch_ram[i] = scratch_rom[i];
-    }
+    // Use DMA mapping to copy flash data
+    SCAR0H = 0x80;
+    SCAR0L = (uint8_t)(SCRATCH_OFFSET);
+    SCAR0M = (uint8_t)(SCRATCH_OFFSET >> 8);
+    SCAR0H = 0;
 
-    // Fill the rest with nop
-    for (; i < ARRAY_SIZE(scratch_ram); i++) {
-        scratch_ram[i] = 0x00;
-    }
-
-    // Set scratch RAM 0 mapping at 0x0000 and enable
-    SCAR0L = 0x00;
-    SCAR0M = 0x00;
-    SCAR0H = 0x00;
-
-    // Jump to reset function
-    __asm__("ljmp 0");
-}
-
-// Finish segment located at 0x1000
-static void scratch_end(void) __naked {
-	__asm
-		.area CSEG (REL,CODE)
-	__endasm;
+    // Jump to scratch reset function
+    __asm__("ljmp " xstr(SCRATCH_OFFSET));
 }

src/board/system76/lemp9/scratch/include/scratch/pmc.h

@@ -15,11 +15,7 @@ struct Pmc {
     volatile uint8_t * control;
 };
 
-extern struct Pmc __code PMC_1;
-extern struct Pmc __code PMC_2;
 extern struct Pmc __code PMC_3;
-extern struct Pmc __code PMC_4;
-extern struct Pmc __code PMC_5;
 
 #define PMC_STS_OBF (1 << 0)
 #define PMC_STS_IBF (1 << 1)

src/board/system76/lemp9/scratch/main.c

@@ -1,5 +1,4 @@
 #include <stdbool.h>
-#include <stdio.h>
 #include <stdint.h>
 
 #include <scratch/pmc.h>
@@ -81,22 +80,12 @@ void pmc_event(struct Pmc * pmc) {
                 state = PMC_STATE_ACPI_WRITE;
                 break;
             case 0xEC:
-                printf_tiny("RESET\n");
-                // Attempt to trigger watchdog reset
-                ETWCFG |= (1 << 5);
-                EWDKEYR = 0;
-                // Clear processor caches
-                __asm__("mov 0xf7, #1");
-                __asm__("nop");
-                __asm__("mov 0xf7, #1");
-                __asm__("nop");
-                __asm__("mov 0xf7, #1");
-                __asm__("nop");
-                __asm__("mov 0xf7, #1");
-                __asm__("nop");
-                // Exit scratch ROM by going through trampoline
-                __asm__("ljmp 0x1000");
-               break;
+                for (;;) {
+                    // Attempt to trigger watchdog reset
+                    ETWCFG |= (1 << 5);
+                    EWDKEYR = 0;
+                }
+                break;
             }
         } else {
             switch (state) {
@@ -123,7 +112,6 @@ void pmc_event(struct Pmc * pmc) {
 
 // Main program while running in scratch ROM
 void main(void) {
-    printf_tiny("SCRATCH\n");
 	for (;;) {
         pmc_event(&PMC_3);
     }

src/board/system76/lemp9/scratch/pmc.c

@@ -7,11 +7,7 @@
     .control = &PM ## NUM ## CTL, \
 }
 
-struct Pmc __code PMC_1 = PMC(1);
-struct Pmc __code PMC_2 = PMC(2);
 struct Pmc __code PMC_3 = PMC(3);
-struct Pmc __code PMC_4 = PMC(4);
-struct Pmc __code PMC_5 = PMC(5);
 
 uint8_t pmc_status(struct Pmc * pmc) {
     return *(pmc->status);

src/board/system76/lemp9/scratch/scratch.mk

@@ -1,33 +1,17 @@
-# Enable I2C debugging
-SCRATCH_SRC+=\
-	src/common/i2c.c \
-	src/ec/$(EC)/i2c.c
-SCRATCH_INCLUDE+=\
-	src/common/include/common/*.h \
-	src/ec/$(EC)/include/ec/*.h
-SCRATCH_CFLAGS+=\
-	-Isrc/common/include \
-	-Isrc/ec/$(EC)/include
-
-# Enable I2C debug on 0x76
-SCRATCH_CFLAGS+=-DI2C_DEBUGGER=0x76
-
-# Set battery I2C bus
-SCRATCH_CFLAGS+=-DI2C_SMBUS=I2C_4
-
 SCRATCH_BUILD=$(BUILD)/scratch
 SCRATCH_OBJ=$(patsubst src/%.c,$(SCRATCH_BUILD)/%.rel,$(SCRATCH_SRC))
 SCRATCH_CC=\
 	sdcc \
 	-mmcs51 \
 	--model-small \
-	--code-size 4096 \
+	--code-loc $(SCRATCH_OFFSET) \
+	--code-size $(SCRATCH_SIZE) \
 	--Werror
 
 # Convert from binary file to C header
 $(BUILD)/include/scratch.h: $(SCRATCH_BUILD)/scratch.rom
 	@mkdir -p $(@D)
-	xxd --include < $< > $@
+	xxd -s $(SCRATCH_OFFSET) --include < $< > $@
 
 # Convert from Intel Hex file to binary file
 $(SCRATCH_BUILD)/scratch.rom: $(SCRATCH_BUILD)/scratch.ihx

src/board/system76/lemp9/scratch/stdio.c

@@ -1,20 +0,0 @@
-#include <stdio.h>
-
-#ifdef SERIAL_DEBUGGER
-    #include <mcs51/8051.h>
-#endif
-
-#ifdef I2C_DEBUGGER
-    #include <ec/i2c.h>
-#endif
-
-int putchar(int c) {
-    unsigned char byte = (unsigned char)c;
-#ifdef SERIAL_DEBUGGER
-    SBUF = byte;
-#endif
-#ifdef I2C_DEBUGGER
-    i2c_send(&I2C_SMBUS, I2C_DEBUGGER, &byte, 1);
-#endif
-    return (int)byte;
-}