rp2040: Add _ramfunc macro to internal.h and use in bootrom.c and chipid.c

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/rp2040/bootrom.c

@@ -7,15 +7,15 @@
 #include <stdint.h> // uint16_t, uint32_t, uintptr_t
 #include <string.h> // memcpy
 #include "compiler.h" // noinline, __section
+#include "internal.h" // _ramfunc
 
 #define ROM_TABLE_CODE(c1, c2) ((c1) | ((c2) << 8))
 
 // All functions in here need to be RAM-resident, as we may need
 // to (especially for the flash functions) call while the XIP layer
 // is unavailable.
-#define noinline_ram noinline __section(".ramfunc.read_chip_id")
 
-static void * noinline_ram
+static void * _ramfunc
 rom_func_lookup(uint32_t code)
 {
   // Table and lookup function are provided by the BOOTROM
@@ -25,7 +25,7 @@ rom_func_lookup(uint32_t code)
   return fn(table, code);
 }
 
-void noinline_ram
+void _ramfunc
 reset_to_usb_boot(uint32_t gpio_activity_pin_mask
                   , uint32_t disable_interface_mask)
 {
@@ -33,21 +33,21 @@ reset_to_usb_boot(uint32_t gpio_activity_pin_mask
   fn(gpio_activity_pin_mask, disable_interface_mask);
 }
 
-void noinline_ram
+void _ramfunc
 connect_internal_flash(void)
 {
   void (*fn)(void) = rom_func_lookup(ROM_TABLE_CODE('I', 'F'));
   fn();
 }
 
-void noinline_ram
+void _ramfunc
 flash_exit_xip(void)
 {
   void (*fn)(void) = rom_func_lookup(ROM_TABLE_CODE('E', 'X'));
   fn();
 }
 
-void noinline_ram
+void _ramfunc
 flash_flush_cache(void)
 {
   void (*fn)(void) = rom_func_lookup(ROM_TABLE_CODE('F', 'C'));

src/rp2040/chipid.c

@@ -30,7 +30,7 @@ usbserial_get_serialid(void)
 // Functions for reading out the flash chip ID. Adapted from the official
 // Pi SDK.
 
-static void noinline __section(".ramfunc.read_chip_id")
+static void _ramfunc
 flash_cs_force(int high)
 {
     uint32_t field_val = high ?
@@ -60,7 +60,7 @@ flash_enter_xip_prepare(void)
   barrier();
 }
 
-static void noinline __section(".ramfunc.read_chip_id")
+static void _ramfunc
 flash_enter_xip_perform(void)
 {
   ((void (*)(void))boot2_copy+1)();
@@ -71,7 +71,7 @@ flash_enter_xip_perform(void)
 #define FLASH_RUID_DATA_BYTES  8
 #define FLASH_RUID_TOTAL_BYTES (1+FLASH_RUID_DUMMY_BYTES+FLASH_RUID_DATA_BYTES)
 
-static void noinline __section(".ramfunc.read_chip_id")
+static void _ramfunc
 read_unique_id(uint8_t *out)
 {
     uint8_t txbuf[FLASH_RUID_TOTAL_BYTES] = {0};

src/rp2040/internal.h

@@ -14,4 +14,8 @@ void connect_internal_flash(void);
 void flash_exit_xip(void);
 void flash_flush_cache(void);
 
+// Force a function to run from ram
+#define UNIQSEC __FILE__ "." __stringify(__LINE__)
+#define _ramfunc noinline __section(".ramfunc." UNIQSEC)
+
 #endif // internal.h